Flightoficarus

Well, it's not going to happen for a little while, but I'm eventually planning to swap my 305 TBI and T-5 out of my Firebird in favor of some type of 350 and a T56. I thought I was completely set on an LT1/T-56 combo, but I'm going to ask for a final verdict on what I should really go with.

Why these two motors in consideration? I've decided that for the kind of budget I'll be on, and in the interest of getting the car to pass smog, these are probably my best options. An LS1 is kind of out of the question (the other options should still be easy to get the power levels I want out of em), and an old, carbed 350 probably has a snowballs chance in hell of passing smog (That, and I want a fuel injected setup anyway).

This is what I've read/been told so far on each option, based on my research thus far...is it all true?

L98
------
PROS: Easiest, typically cheapest 350 swap for a third gen. Gen I SBC design = lots of aftermarket parts and easy to find parts for.

CONS: Earlier TPI systems tended to be a bit finicky and problematic compared to later years, Stock TPI intake is very restrictive on top end (less stock HP than LT1). Lower (I'm assuming) fuel economy.

LT-1
---------
PROS: More stock HP than L98, F-body/Corvette versions use aluminum heads (less weight). Slightly better fuel mileage, still a cheap swap.

CONS: Modification of the Firewall is required to fit the A/C compressor into the third gen engine bay, making it a bit more involved of a swap. Some say it's only marginally better than the L98.

Comments on that? feel free to correct anything that isn't true, lol. Essentially, my question is which engine is the better option for a target power goal of between 300 and 350 (crank) HP, that is cost friendly, and can pass smog? (or some way to get past it?). Thanks!

89fbirdformula

if you're low on funds...do an l98.

however, a nicely tuned heads/cam/intake LT1 will FLY.

ive always wanted to find another 82-84 t/a without GFX, and stuff a nasty lt1 between the fenders...and i dont know why haha.

if i ever find one, it'll get a hci lt1/t56!

InfernalVortex

iTrader: (4)

I'd go LT1 and ditch the A/C all together and not look back. Those things can go so fast with massive cams due to the compression ratios they can safely run.

Klortho

Go with the LT1, it's not the firewall that has to be modified for the a/c, it's the k-member and if you have a BFH it takes all of 5 minutes to make it so the a/c clears.

Jim85IROC

iTrader: (2)

I'd stick with a Gen 1 small block. The LT1 is kind of the "in-between" short lived motor. There's decent aftermarket support for it, but nothing compared to Gen 1 or Gen 3/4 stuff. Any heads/cam upgrade that you do the LT1 can be done with the same results to a Gen 1 motor, and can usually be done cheaper, and with a lot more options. You also don't have to deal with the optispark or as much ECM harness & wiring issues.

The only benefit that I really see for the LT1, is that they are cheap in salvage yards, so if you're on a super tight budget and don't plan to modify the motor later on, the LT1 is a viable option. If you can spread the budget a little farther, you can move into LS territory with far greater results, or stick with a Gen 1 motor and throw some parts at it, again with better results.

Klortho

what ecm harness/wiring issues? The only year LT1 to use an ECM was the '92-'93 model, in '94 they went to a flashed base PCM. There is nothing wrong with the opti as well, you can take an LT1 further than a Gen 1 for the same amount of money, tuning is easier on an LT1 than a TPI car as well.

TxTtopZ

Dont waste your time swapping out engines, wiring harnesses, transmissions and everything else for an LT1. The SBC can make just as much power and the drivability will be no better with the LT1. It's just a reverse flow cooled SBC and in fact, with some machining the LT1 stuff will bolt on an SBC. Not only that but I have had a couple LT1 cars, and the optis are as they say.... JUNK. If your going to go thru all that trouble, go LSX, if not, try modding what you have first, you might be surprised.

EDIT: I should have just said JIM x2 or +1, you said it buddy.

Klortho

I don't know why people continuously say that opti's are junk, I have one right now sitting on a motor that has 150k miles on it, I can go out right now and the motor will start right up no problems at all.

I'm going to say, go with the LT1, you won't be disappointed in it if you're on a budget, the internals are better than in a standard SBC, the reverse flow cooling allows for higher compression ratios, the intake is a better design than a TPI intake, the motor makes 285hp in bone stock form and gives you lots of room to build on

89fbirdformula

x2..

ive had plenty of lt1's...strong running motors..

i sprayed 325 through my bonestock 97 ws6, car went 11.70s @130 on a 275/40 kuhmo, through a 4l60e...

also had a lloyd elliot formula, stage 2 package...car went 11.40s on nuts...

FYI, LT1 can be ran on stock TPI harness/computer...

you only need a modified LT1 intake for the rear dizzy..and you're good to go.

TxTtopZ

http://www.youtube.com/watch?v=oORyw5MfbRA
Here ya go... lol OUCH!

89fbirdformula

what exactly does that prove? that a stock car, with a stock motor...got beat by ford's 500hp supercharged shelby?

all this talk of gen1sbc being so easy/cheap to mod...

an LT1 with ported FACTORY heads, and a cam, will throw down 380/420 rwhp depending on how mild/wild you go on the cam..

an L98 with ported FACTORY heads, wont even come close to that number, and it wont even with aftmkt heads.

Now you have to address the TPI intake issue, its 600/700 MINIMUM for a decent intake, even going stealthram{ i have 800 into mine with fittings}...LT1 will do it on a stock intake.

TxTtopZ

It proves after the swap, the car will still need heavy mods and all that mess is not going to make a difference on the outcome of the mess when he can just put in an L98 easier, mod that and still be just as fast... I am not against lt1's. As I said before, I will say again, theres NO reason to do all that work for an Lt1! Can u see that? Theres NO REASON to do ALL THAT WORK for an Lt1! I'll say it one more time, there is NO REASON to go LT1 from L98.
L98 has MORE parts
easier to swap
more tuning options
gets the same power
bolts right in
retain ac easier
and the optis can give problems and they are expensive and it takes considerable time to change one.

TxTtopZ

It proves nothing, just thought i'd post it up... well, it does prove after the swap, the car will still need heavy mods and he would be better off to go LSX. Theres just not enough differece in the L98 vs the LT1

89fbirdformula

Do you have any actual experience with lt1's or are you just typing based on your opinion?

Because you are wrong on so many levels.

L98/LT1 is the same as far as swapping goes...like i said, an lt1 can be ran on stock TPI electronics, all thats needed is a modded lt1 intake for dizzy.

They do NOT get the same power, mod for mod, PERIOD.

and your opti bantering, is bs..the reason why optis go bad, is usually the water pumps leak, and **** coolant all over the optical sensor,and ruin the opti...and then, alot of owners choose to buy the cheap chinese junk optis at autozone...and then complain when they go bad. ive had several lt1 cars, and a few with well over 150k...all with *gasp* not a single OPTI issue. and by the way, it takes 45 mins to change an opti...

as far as retaining a/c..id be willing to bet that 80% of the thirdgens around, do not have functioning a/c anyways...

you show me a Stock bottom end, heads/cam L98...that puts out 400rwhp.

as mentioned before,you can get away with ALOT because of the compression/reverse cooling..my HCI formula had milled lloyd elliot ported heads, gasket matched intake, and one of his cams, thin HG, compression was over 11 to 1, and it made tons of power

Jim85IROC

iTrader: (2)

The only benefit that the LT1 has, from a power-making perspective, is the superior cylinder heads and the intake manifold. Sure, with a couple bolt-ons, the LT1 will continue to be faster, but once you step up to REAL mods, like heads/cam/intake, then the LT1 just lost all it's advantages, but you're still stuck with the disadvantages.

Like I said before, if you're keeping it stock or close to it, the LT1 can make sense, but if your goal is real power, then the LT1 is not the best decision.

TxTtopZ

Wow dude, you just love to argue. lol
Ive had problems with factory GM opti's, hence why would one need to go to Autozone in the first place? Because the water pump leaks??? WOW, so thats 2 problems we now have.
Have I had an LT1? Does a 1997 Trans Am count? Her name was Snow White.
I have yet to see an Lt1 make more power than an SBC and they ARE NOT THE SAME to swap in! What are you thinking? My 305 Lb9 crap swaps DIRECTLY over the l98! The LTx IS NOT a direct swap. Sorry. Im not even going to keep arguing with someone who wants to be right or have the last word... go for it.

OP The Lt1 swap is a lot of work for a Gen 2. I would be smart, and get an Gen 3. thats my vote, and 16 years of working on cars isnt going to change that, or anyone else who has had years experience, unless they just want an LT1. IF you just want one, why start this thread? Just do it. Otherwise, go L98 or LS1. There's just not enough out there for the Lt1 Good Luck.

89fbirdformula

i doubt he is trying to make 600/700rwhp...

Dollar for dollar, the LT1 wins here, if im wrong, please prove it? ive built both many times, and i know which made more power for less money.

ive had HIS goals in mind, he said 300/350 hp..an lt1 will make that ALOT easier, and FAR cheaper then a L98. i cant see any argument with that?

if his goals were all out radical power, then yes id agree, stick with a gen1sbc.




I guess im not like 95% of vehicle owners on this planet, who let there cars FAIL, before they fix things/do preventative maint...

im really not trying to argue, but your advice is kind of flawed, you seem ot have some bias against lt1's..


Like i said BEFORE, an lt1 is NO harder then swapping in a l98. and if you're going through the trouble of a complet eharness swap...its basically the same level of involvement..

however, an LT1 will run perfectly fine on a tpi harness/computer/dizzy.

everything I have mentioned, meets his goals, EASIER and CHEAPER.

To the op, if you have any lt1 swap questions, feel free to PM me, im more then willing to help.

TxTtopZ

So why would a 23 degree head flow better on a 4" LT1 bore than a 23 degree head on an 4" L98 bore? Because of the reverse cooling? Thats all relative to water temp, which can be controlled, it doesnt matter which it goes to first that being equal.
And for the last time, i am saying go LS1, not L98. But I wouldnt go LT1 over L98 either. thanks.

Jim85IROC

iTrader: (2)

Fair enough, for 300/350 horsepower, with an LT1 you're talking headers and a cold air intake for the most part.

Then again, with TPI, you're not looking at big mods for 300hp either... but by the time you add up a base, runners, rockers, headers, etc... it can start to get expensive. But as soon as you start talking heads/cam/intake, it's more of a level playing field, and we all know that we're never happy with whatever horsepower goal we think will suit us in the near-term.

TxTtopZ

You ALWAYS want more... that is why I say L98.. Im glad we agree, but FWIW I think the OP has lost interest.

89fbirdformula

meh, i somewhat agree...

i think, all variables the same, with the only difference being lt1 shortblock vs l98 shortblock...LT1 will make more power, and its been proven.



see above post..

but yes i agree he's lost interest.

Flightoficarus

Hey! No one has lost interest!

But I see I've managed to spark a passionate debate on these engine choices!

I thought that it's pretty much impossible to get away with any cam, heads, or intake mods if you need to pass smog? Or am I mistaken? I've heard of the Holley Stealth ram intake for the L98 engines, but that they're not smog legal, and they won't fit under a Firebird hood (I plan to throw on a formula hood, but I want to keep a "stock" look). And I've heard the other options that will fit under a 'bird hood, and/or pass smog are very expensive.

On the LT1 side of the debate, I've heard that there are both parts you can buy to either delete the A/C, or mount the A/C compressor in another area, to make the swap easier. How much extra trouble is an LT1 to swap in?

No matter which engine I go with, I'm looking at exhaust and headers, since I'm going to have to replace those awful, restrictive stock units that come on the 305. I'm also looking at an aftermarket air box/cold air intake, and basically anything else I can get away with to meet or exceed my goals.

Here's anothe question: Which engine weighs less?? An aluminum head L98? or an F-body/Corvette LT-1?

I have no engine prejudice here, I'm just concerned about cost, smog legality, ease of the swap, and any weight advantage is a bonus (Since the T-56 will already be helping me out w/the front-rear weight ratio anyway). Thanks!

89fbirdformula

if your concerned about weight,cost, smog legality and your power goals.

LT1 clearly wins here..

Find a 90-92 TPI harness, have the lt1 intake modified for a rear distributor, and you're pretty much set to go.

run a 89-92 TPI style throttle body, put some headers on it, a decent tune, cold air, and it'll do 270ish rwhp on the conservative side, cam only if you choose, 330ish rwhp...

heads/cam package can be found for 1k/1200 used either from lloyd elliot, or advanced induction...and 400+ rwhp,probably 420+ through a 6spd

Flightoficarus

So basically, it sounds like it'll be damn easy to hit the good street-machine numbers I'm after with the LT1

I'm still curious, I thought the LT1 weighed like 30-40 lbs more than the L98 did? Most people I've talked to have told me the LT1 weighs about 60-65 lbs less than a 305 TBI, thanks to the aluminum heads on the LT1.

Also, any elaboration on possible ways to make the A/C compressor issue less of a hassle w/the swap? (assume I want A/C). Does the LT1 bolt on to the stock motor mounts like a 350 TPI would since they're both 350's?

And finally, I've been told that despite fewer available aftermarket parts for LT1's than SBC's or LSx engines, that many parts are interchangeable between LT1s and SBC's. What are they? what isn't interchangable? (besides the block).

Pretty much, the extra work involved and lesser aftermarket parts are my only concern w/the LT1 atm. Is there still better support for it than TPI setups? And do heads, cam, or intake mods pretty much automatically guarantee you can't pass smog?

Thanks for all insight!

Carlos773

iTrader: (3)

I know its a couple of months old but was an interesting read.

As for your question Flight, If I am correct from my research only Fbody/Corvette Lt1s came with Alum heads.

As for the motor mounts, sbc motor mounts work fine. Passenger side mount on the Lt1 is slightly different and some have had problems with aftermarket mounts.

For the A/C a search should bring it up, I do not plan to keep my A/C, I removed it even when my L03 was in there.

Lloyd Elliot offers Emission friendly Head/Cam work for the LT1. Check out http://www.elliottsportworks.com/lt1.html.

I myself is looking into a LT1 swap and have thought about the L98 swap as well for my L03 replacement and the LT1 seems like the right investment. I can pick one up for around $500-600 with anywhere from 70k-110k miles on it with harness and ECM.

After I get my LT1 in, I plan to run his LE2 Head work package with his 230/234 custom cam, but thats probably a long time before its ready for it.

StevenB L98/LS1

Because you are wrong on so many levels.

L98/LT1 is the same as far as swapping goes...like i said, an lt1 can be ran on stock TPI electronics, all thats needed is a modded lt1 intake for dizzy.

They do NOT get the same power, mod for mod, PERIOD.

and your opti bantering, is bs..the reason why optis go bad, is usually the water pumps leak, and **** coolant all over the optical sensor,and ruin the opti...and then, alot of owners choose to buy the cheap chinese junk optis at autozone...and then complain when they go bad. ive had several lt1 cars, and a few with well over 150k...all with *gasp* not a single OPTI issue. and by the way, it takes 45 mins to change an opti...

as far as retaining a/c..id be willing to bet that 80% of the thirdgens around, do not have functioning a/c anyways...

you show me a Stock bottom end, heads/cam L98...that puts out 400rwhp.

as mentioned before,you can get away with ALOT because of the compression/reverse cooling..my HCI formula had milled lloyd elliot ported heads, gasket matched intake, and one of his cams, thin HG, compression was over 11 to 1, and it made tons of power[/QUOTE

I have ac in BOTH my third gens. 91 and 90 both L98 cars, 90 being built custom cam, aftermarket heads, headers, exhaust, both msd ignition kits, accept my 91 is just a stock L98 with exhaust and MSD. the 90 l98 blows the lt1 away from a dead stop to close to 120, my 91 only does about to 80 before the lt1 goes by. My choice is the L98 u can do easy, cheap ways in just a stock L98 to have fun in, but my advise is always change the l98 heads, there junk.

Carlos773

iTrader: (3)

So you went up against an equally built LT1? Your 90 went against a LT1 with Cam, Heads, Exhaust, etc? I take it by your 1991 with just exhaust/msd statement that that is not the case.

The whole argument here is him going to either a L98 or LT1 from his L03. The LT1 is the better choice.

Jim85IROC

iTrader: (2)

let's get back to this "LT1 short block is proven to make more horsepower than an L98 shortblock" nonsense. Are you talking an apples-to-apples comparison in which both motors use the same pistons? The only real differences I see between an LT1 shortblock and an L98 would be compression ratio due to piston design. The only REAL differences are in the heads & induction, which aren't part of the short block.

StevenB L98/LS1

The 90 is also a edlebrock high base intake which was already on the car when i bought it, and yes the facts are true. Stop thinking just because an L98 with such a restrict intake system that an LT1 out power it in every shape and form.

The car has aftermarket heads, dont know know specs, the shop guy while rebuilding it put in aftermarket heads from summit, custom mild cam, headers, exhaust, msd higher spark, throttle response is amazing, and tune for the cam for the 90. the LT1 have no ***** at off the line, there just a higher rpm, top end motor, and btw my friends 95 lt1 t-56 car was a full bolt on tune car and my l98 was beating it until 115 to 120 when he came up aside and took off.
everybody has there opinion dude, im just saying u can just as much fun old school

Thirdgen89GTA

iTrader: (5)

LT1 has no torque?

Are you insane? It may not have the mid-range boost that the LTR setup gives, but its CERTAINLY plenty strong. My B-body LT1 swap will light the tires in 1st and most of 2nd gear if I just jam the throttle down from a stop. This is a full weight GTA, race weight is near 3500lbs.

Stock for stock, the LT1 makes more power over a broader curve. This is the result of the short runner intake allowing it breathe well at high RPM, as well as increased headflow. So bone stock to bone stock its no question about which engine is better. The LT1's also used a smaller cam profile to achieve more power.

My friend had a LT1/M6 4th gen, a 30th Z. That thing never lacked for torque, every time he put his foot down the engine would eagerly respond, it was instant gratification.

I'd go 5.3L Gen3 or Gen4 sbc if i had to do it all over again, they are too cheap and plentiful. They are better in every way, can get them out of trucks with harness/pcm for $450 locally if you look.

86White_T/A305

Lets not confuse the Op but L98 to Lt1 are very similar and not at the same time.For what he wants..both can and will get the job done and can be done for almost the same price depending on where he gets his parts from.

The L98 is a beast for bottom end torque off the line which can and has put a few lt1...and ls1 cars to shame,off the line.mid range to top end power is where the L98 lacks.Yes you can build a L98 to breathe more uptop with a stealth ram or miniram etc..which puts the induction side on par with the stock lt1 intake or slightly better.The main issue with the L98 if it stays fuel injected is tuning.they can be very picky to tune when fully built to get the full power out of them.

Lt1s stock make more power and is a closer starting point for the power goal your after.its pratically the same amount of work to swap in physically and for wiring..no real pro/con there unless you choose to run the lt1 on the tpi ecu..which these days..guys run an ls1 ecu on lt1s with much better results having coil per cylinder.The opti issue isnt as big of a deal as ppl make it seem..having owned an lt1 corvette and changed it within an hour..dont let that discourage you as they can run great and last a long time.lt1s shine in the midrange more than the tpi.. the infamous butt dyno is why alot of us love l98 and "feel" faster than we are.mod for mod..lt1 will come out ontop and be better street mannered then the tpi with better gas mileage.

Both are badass motors..just gotta look at what suits you better.L98..torque monsters but not top end screamers,Lt1 midrange flyers...LS1s..highway screamers lol.

Ive gone from 305 carb to 350tpi,to 383 stealth ram,to lt1.and working on making an ls1 sleeper.

Gibson

having driven both back to back, there is a reason why chevy went from the l98 to the lt1...the lt1 just kicks the l98's *** in stock or mild build form. LT1 FTW!

Carlos773

iTrader: (3)

Everyone does have their opinion and I dont agree with yours. I was trying to get across that you putting up your H/C L98 against bolt on LT1s proves nothing against the LT1. @89 GTA, I need you to show me where those $450 5.3s are

scrubbin627

LT1. No doubt about it

Grumbles

I put two bottles of alcohol into my tank and the sniffer thought my (over)carbed 305 was a prius

Flightoficarus

So, it seemed like this thread got going a bit again for a second!

Ok, I have to admit. I've continued to do plenty of research and debating on this matter, and yet, I'm still not 100% sure on my decision between these motors. They both seem to have enough advantages and disadvantages that it seems more like a personal preference choice.

There are a few things I'm curious about that I'm asking the engine gurus around here that will really help my make up my mind!

- Is Reverse-Flow cooling bad? Someone in another thread I was reading referred to it as being not a good thing. Why is that?

- Does an L98 w/aluminum heads really weigh more than an F-body/'Vette LT-1? I haven't been able to find a clear answer on this one, but I would imagine they would be very close, since the Gen II engine is basically a modified SBC. I have heard from somewhere that some changes in the LT-1 design actually added weight, but I can't remember where...

- Are there any other good, fairly inexpensive intake options for an L98? Everyone mentions the Holley Stealth Ram, but they won't clear under a Firebird hood. This car is essentially somewhat of a resto-mod project, and I'm trying to keep the car looking stock (no crazy 4+ inch cowl hoods or 4th gen style ram air hoods). Plus, I dig the turbo bulge hood, hence why I got one for my car . What about Vortec TPI? Passing emissions is another concern too, but it's mainly about keeping the smog gear on the car and meeting number criteria here (basic tailpipe sniff/dyno test).

Lastly, these are a few reasons I'm starting to consider an L98/350 over LT-1.
- Easier to swap in.
- More aftermarket parts/cheaper replacement parts (including 50 state legal aftermarket heads, from what I've been able to find).
- Can transfer over/use certain parts I buy for my current 305 with a 350.
- No Optispark (not that big of a deal personally, but it sounds like something I'd rather not deal with given a choice).
- It just sounds like if you're gonna go to extra trouble, then you might as well go LSx.

Phew! A long post, I know, but it's how I'm starting to feel. Any elaboration on my questions/options is greatly appreciated!

scrubbin627

Is reverse cooling bad? NO

Reverse cooling is why the LT1 is so awesome. The reverse cooling allows you to run more compression, more spark advance, and resist detonation much better than the traditional 350.

The LT1 is a better motor than the L98 kind of like the LS1 is better than the LT1. Its the natural evolution of technology. They all have good and bad points, but unless your on a budget or just want the easiest way out there is no way I would pick a L98 over an LT1. LT1s make more power from the factory and respond better to mods, theyre also way cheaper than an LS1. Just my

86White_T/A305

Fyi: Holley stealth ram fits fine in a stock transam hood just cut the center hood brace right around the throttle body and give a few inches more to prepare for motor vibration.My hood closed without cutting it but it did rest ontop the very edge of the throttle body.lots of posts and pics on the forums to show this.Dont let that stop you from getting the hsr benefits to build a motor.

Cant quite remember but depending on which yr or car it came from..the lt1 was lighter than a sbc if it was an aluminum block with aluminum heads vs the sbc havig cast block and aluminum heads.someone please confim this..been awhile since i looked up those weight saving numbers lol.

Reverse cooling isnt bad..the lt1 needed to be this way based on the way the motor would build heat naturally and reverse cooling made the motor more efficient and reduced temps faster than sbc.Dont know if anyone has tried that on a sbc and have it made any difference.too many factors involved in the cooling process for it to matter for me..lots can be changed to keep a motor at a targeted heat range.

Going from a 305 to 350 on a budget would be your easiest option with the parts yo can swap over and that saved money can be used for some upgrades to the 350 and still be fun and 50 state legal.

five7kid

iTrader: (14)

There was never a production LT1 aluminum block.

Reverse cooling was driven by emissions standards. Giving the combustion chamber first crack at the coolant flow made combustion temps easier to control. When that is consistent, designing the rest of the engine/control system to get the best power and economy within the allowed emissions was easier. Unfortunately, somebody besides GM had a patent on the reverse cooling concept, and since they didn't license it from the patent holder (oops), they had to come up with something else - hence, the big bucks spent on the clean-sheet LS design.

scrubbin627

I never knew this. I always figured it was distributer problems that plagued the LT into retirement.

Do you know who had the patent?

five7kid

iTrader: (14)

I've heard Smokey Yunick.

The Optispark "problem" has been blown completely out of proportion. Just like the Corvair, the problem (for what it was) was fixed before it was common knowledge.

scrubbin627

Interesting.

I agree the opti problem is blown out of proportion, I have had minimal problems with opti's the past 10 years Ive been driving them. The moisture problem's in the early opti's was fixed, seems the biggest problem now aside from running through a creek or water pump failure is the rotor flying apart. MSD has the best looking cap/rotor, Ive been lucky so far.

Flightoficarus

Hmm...interesting info on the reverse-flow cooling five7kid! The question I'm still have though, is that if a high-performance water pump can substantially improve the cooling speeds of a small block? Is the reverse-flow system just one of multiple ways to more efficient cooling?

And about the stealth ram. Just how much stuff goes off the engine to install one? Not sure if this is all true, but I heard you must remove things like the EGR valve, and other emissions components in order to use it. Are there any other good intake systems out there other than the HSR, Miniram, and Superram for the SBC? And what all can be done to a TPI to improve on it? Or is modding a TPI system pretty much a waste? Thanks!

five7kid

iTrader: (14)

It isn't cooling efficiency that is improved with reverse flow, it is cooling effectiveness. You're using the cooled coolant to cool the most critical area first, that's all. The benefits from that are what you can do because of that.

The HSR eliminates EGR. I've heard stories of being able to get it through emissions, but I doubt that was a strict inspection criteria.

You need to check for more details on the TPI forum, but I believe the only one that retains EGR is the Edelbrock base. You can make TPI run much better than stock, but it takes careful choice of parts, and skilled ECM tuning.

cuisinartvette

You can well surpass your goal of 300hp with an L98 less involved converting and tons of aftermarket support. Brackets ecm etc much simpler and have no issue passing smog. If you wanted more then go straight to an LSX but youll spend bux doing it.
Get an efficient cylinder head compression is no concern but being as it will have to pass smog it wont be anything crazy anyway. If you can pass with a converted LT1 intake youre about on the same power level anyway.

Flightoficarus

Well, when I took the bird in for a smog test last time, They basically just popped the hood to connect a device to measure RPM's, and did the traditional tailpipe sniffer test . I believe the only real requirements here are that the emissions stuff needs to be on the car, and that it can pass the sniffer. When I took my DD in though, they just checked for codes, and gave me the green light, lol. Either ODB-II testing is lest strict, or they just assume I'm up to no good when I pull up in an old Firebird!

Either way, I've done much contemplation about this, and I have finally decided that I'm going SBC/L98 instead, and this is why..

- On a budget
- Simplest swap/can most likely find someone to lend me a hand w/it (and avoid beastly shop labor fees)
- SBC and LSx has much better aftermarket support than LTx
- I want the old school sound/vibe with this car! (And even if it's purely aesthetic, I gotta say I LOVE the look of a TPI or HSR setup on an engine)

Thanks for all the help you guys have provided! but I have one more question regarding the L98. I noticed that early L98's used MAF, and later years used Speed Density (while making a bit more power too). I've heard some people say in theory, that MAF should be the way to go, but that in practice, Speed Density is what you want. Is this true?

Carlos773

iTrader: (3)

well i was also on a budget a uery strict one. I had under a grand to get the old 154k lo3 so far i am not even close to maxing my budget. Picked up my 97 lt1 for 625 add gas and make it 650 even. I had the engine hoist loaned as well as the engine stand. So add the cost of that and i will still be under a grand even more if i resell the hardware. So far i have spent 70 on the engine being ac delete pulley and new belt. Harness is almost done and engine is going in this weekend. So budget has nothing to do with it. I would not ever swap in a l98 or lb9 unless it has to be smog friendly.