OK guys I just want some clarity on this subject. I had a debate the other day with a couple freinds.

Both guys have 89's

One guy has a camaro with an LT1/700R in it.
He spent approximately 3000.00 and ridiculous hours on it.
Respect for doing it of course.

Other guy has a camaro with L98 /700R in it.
He spent 1500 on his for heads / Cam combo and did it in a weekend

Now the debate was. Why would you take out a number matching L98 and spend half a year and 3000.00 to get a 300hp 350trq motor put into your car

When you could spend 1500.00 and a weekend to take your L98 and bang out 350hp and 375trq still have a number matching ride..With gas mileage mildly affected..

The first guy said in response the gas mileage is better. The second guy(L98) said why the hell are you concerned with gas mileage when you own a sports car?

So the question to all other third Gen guys which way would you go?
Guy with LT1 OR GUY WITH L98.

 

If I already had a good running 350TPI I would mod it.
Now I already got in this arguement with people on here and most of them would do an LT1 swap.

To me at that point you just drop in an LS1. Even with stock manifolds to save money it's still putting down more RWHP then the LT1 does at the crank stock.
Again that's just me.
They're going to come in here and tell me how that's too expensive.

As for MPG I bet the TPI could do as good with a tune. It's naturally going to have much better torque at crusing speed and city driving then the LT1.

 

IMO very humble opinion...alot can be done with an L98--they have the best low end torque. But utlimatley an LT1 can male more HP--esp at high rpms

 

L98 - batch fire.
LT1 - sequential injection.

L98 - long, tuned runners, low RPM and flow potential.
LT1 - short runner, high RPM and flow potential.

L98 - pull the chip, erase it, rewrite it.
LT1 - hook up the laptop, do your tune.

Heads & cam for an L98 is about half way there. You'll have to spend another $1000-$1500 in TPI hardware just to take advantage of the cam & heads. And that's about all you will get out of it, while the LT1 is just beginning.

 

1. it doesnt take half a year to do an lt1 swap, and im sure there are some people who have taken that long to do heads / cam. I could do the LT1 swap faster than your friend did his heads / cam swap in a tpi car. Guaranteed.

2. numbers matching ? 99% of thirdgens around will never really be worth anything to make numbers matching matter.

3. Theres a good bit more to this supposed 350 HP TPI than just installing heads and a cam, the intake doesnt flow for squat FACT, not to mention the computer isnt all that great, the LT1's much newer efi system makes it better, hands down, drivability, power, emissions, and fuel mileage. To a lot of people its a lot more than just a peak HP number.

4. Even if you did get 350 HP (crank) out of the heads / cam tpi 350, you are in reality, maybe 20 HP ahead of the guy with an LT1 swap with just exhaust / air intake. So the guy that spents the extra $400 or so slipping a cam into the LT1 while doing the swap, which isnt that hard to put down 320-350 rwhp with the stock unported heads, so whats that 400-430 crank roughly ?

5. The guy who is smart enough to swap his L98 for an LT1 also finds some other sucker who thinks he's going to make good power out of the L98 for cheap, and gets a good chunk of his LT1 money back just selling off the L98 crap.

6. On top of the LT1's better efi setup, intake that flows more, the LT1 swapper also loses weight compared to the L98, even if the L98's got alum heads, the LT1 still will weigh less, then its easier to work on, anyone who's ever removed a tpi and installed one, without leaving out bolts, its a pita. The LT1 also gets you min the 124A alt vs what 105 L98 ? or the better 140A.

 

Going from L98 to LT1 is not worth it. Going from L03,LB9 or any other 305 to LT1 is worth it. Going from L98 to LS1 is worth it. Just my opinion of course.

 

Then you havent had to actually disassemble / assemble a TPI intake much, just the ease of working on it alone is worth it, let alone all the other benefits.

 

Take off the TPI intake, sell for $200.
Buy HSR for $550

But then TPI is fine till an easy 300HP.

 

Correct, swap the intake. Hell if you can still find them swapping a converted LT1 intake is still one of the best options for L98s.

 

Good, you've upgraded the top end of things for $350, and still have lesser flowing heads, you also need a reprogram just to get use out of this, good bit of time money and effort required there...

or Sell entire TPI setup for $400, serpentine for $100, L98 longblock for $200, buy LT1 for $750 (not that hard to do) say $300 for install parts, you've spent the same $350, yet also got much higher flowing heads, and removed a good bit of weight, while going to a better efi computer.

 

Yep, cheapest intake upgrade out there thats bolt-on. The LT1 intake swap is another plus but isn't as clean, and you'll have to mod the intake to fit.

Swapping from L98 to LT1 isn't really worth it if you have a good running L98.

L98 + HSR + Vortec heads + and a mild cam is good for plenty of street power. Add headers and get more.

I built my L98, didn't see much worth in a LT1 swap. However when the L98 went boom I sold my HSR for $600, the long block for $300, and the rebuilt trans for $600. Got $1500 out of the old setup, not including the harness and ECM I sold for another $150, and bought a LT1/4L60E for $1600, with a plugin harness.

Add headers I already had and I'm above what the old L98 was making, and now i have aluminum heads too.

Granted, I needed a DD box for the speedo but everything else was easy as pie.

So in some cases its worth the swap. In others, not so worth it. I pretty much came out ahead of the deal.

 

What are you using the DD box for ? There is no reason to have it with an LT1 swap unless you are using it for the cruise signal.

 

Sorry but I have to ask... What is a HSR?

 

Holley Stealth Ram intake manifold.

 

Need to convert the VSS signal into something the speedo can read, works for cruise as well.

 

i'd agree the LT1 is much better platform to work with

it has abit stronger internals, better ecm control, good heads that can rival aftermarket heads when fully ported and there are several GREAT LT1 head porters out there.

LT1 makes smoother torque curve instead of TPI's peaky power. LT1 makes higher rpm hp. You can get a 1700 dollar heads/cam package for LT1 that will make proven 400whp and run 11's all day long.


The only way to keep an L98 competitive is with HSR swap/miniram swap or converted LT1 intake

If you have a good solid shape L98, then you can add good heads/cam/intake swap to make good power, but it will cost you more than the LT1.

LT1's can be had for 1500 bucks for a good one, some less. 1700 in heads/cam and 1000 in other supporting mods/tune will make 400whp easy.

An L98 needs good heads and needs them shaved down to keep compression up like LT1's have. So figure 1000-1200 dollar aluminum heads, custom valve train to handle a good cam, and milled to 58cc to keep compression up, thats another 500-700 bucks in head work/springs/etc
Then 650 for HSR/fuel lines, then the 300 dollar cam.... and you still need a tune which not many ppl do for 80's ECM's. THe LT1 is looking good

 

Have you not already installed it ? The LT1 speedometer output is 4000 pulse / mile from the pcm to the instrument panel, its the same that the thirdgen input to the speedometer is. The only time its needed is if you are retaining the stock thirdgen cruise control system because it gets a 2000 pulse / mi signal from the buffer box (tbi) or straight from the ecm (tpi, v6).

 

Some mighty fine points gentlemen.......

I have to say I agree with the point that if you have a 305 do the LT1 swap

I like the point that if you have an L98 and really want to swap it out go for an LS1.... even better.

On the other hand if you have a good running L98 ....I would most likely keep it till you done with it or its done with you.

Yes you can upgrade and do alot more with an LT1 but The Grass is not always green'er on the otherside. People tend to forget you have to cut fertilize and water that grass to make it prosperous.

I have a theory.....Some people are perfectionist with their cars and are always evolving with it others are content with their L98 dinasours and when done with it they go out and buy a newer car with an LT1/LS6 already in it I suppose...

 

i happen to prefer the thirdgen looks over the 4th gens... its just that they have better powertrain options than thirdgens...so its only logical to do a LT1 swap.

I kinda kicked myself in the butt for not doing a LT1 build when i had the chance. I could have gotten a complete 21K miles Lt1 that was in a flood for 500 bucks or maybe even 400. All it needed was a tear down and refreshening and it would have ran great. instead i spent 650ish on a HSR swap. So i would have been doing cam/heads this winter instead of doing a 383 HSR build and spending abit more money

 

A complete non-hack job LT1 swap is gonna cost more then a grand i really don't care what the figures people come up with there head are. To do stuff right engine swaps ALWAYS cost more then you figure. Just to give an idea my L98 would run plenty of LT1s...bolt on only. LT1s ran high 13s...my car ran mid to high 13s with a T56. Full exhaust and some intake bolt ons thats it.

Going from L98 to LT1 is NOT worth it unless the L98 has serious problems that will cost a lot of $ to fix. Blown up or a hacked up harness, something like that and then an LT1 swap maybe worth it. But if the L98 is healthy there is no reason to stop bolting on. GEN1 or GEN3 IMO. Skip GEN2 unless you have a V6 car or a 305 then it maybe a good choice for you.

 

my buddies 170K mile LT1 with a mail order tune/exhaust only, 3.42 gear car ran 12.90's at 106. Thats stock suspension and stock style street tires, stock auto trans with no converter.

Thats faster than my full bolt on (minus 1.6 rockers that day) L98 which had slicks/skinnies for weight reduction and 2800 stall/full suspension. I ran I ran 13.2's at 101.xx that night. He cut 1.9 60 foots while i was in the 1.74 range. Still caught me on the big end with my huge off the line advantage. he trapped near 107 to my near 102. LT1's are alot stronger with the same mods than a L98 will ever be. LT1 is still a smart upgrade in MY opinion.

 

Well i've never seen that, and thats just not common of them. LS1s run around 13.3-13.6 worse then that depending on driver around here. I have never seen a stock LT1 car run quicker then 13.5. Just like i normally do not see L98s in the 13s but i had one that ran 13.5 so i know what they can do.

There is too many ifs, ands, and buts to this argument we can all agree to disagree on some stuff. So ill leave it at that. For the work thats involved with swapping to LT1, i would just go LS1 thats all im saying.

edit - Sorry obviously my L98 was not stock when it ran 13.5. It ran a 13.9 with only slp runners and a 2.5" flowmaster catback. Stock auto with 3.23s. I have seen several LT1 cars have trouble even breaking 13s stock. They only ran .2-.4 tenths quicker then L98s. Nothing a bolt on L98 can't touch for a little bit of money.

 

1. Yes LT1's ran high 13's, in a 3600 lb car, put that same engine in a 3400 lb 3rdgen, which also lightened the car since the LT1 weighs less, not exactly a high 13 sec car anymore is it once its lost 200-300 lbs.

Gonna cost more than a grand huh ? ALWAYS, well i'm glad you've set that in stone, I guess being that i've done 5 different LT1 thirdgens, that I wouldnt have any idea how to pull the swap off for that price.

 

LT1s weigh MAYBE 50-75lbs less then an L98...with what alum heads and a lighter intake manifold cause thats it...

Like i said if the L98 is blown swapping to an LT1 may not be that bad of a choice after all. Personally i would not take a healthy L98 and swap it to LT1, thats all i'm saying.

 

LT1's running 12's with bolt ons is very common, but majority will run low 13's. They make 300-320ish whp with full bolt ons thru a manual 6spd. Some autos are near 300 tho with bolt ons. His car with stall/slicks would do 12.6's easily. My car only made 254whp full bolt ons just about. probly would have made 260's with a better tune, and maybe 270-275 thru a manual. LT1 is still 30-50 hp MORE.

Getting a L98 to 320whp will cost as much as a LT1 swap with bolt ons. I dont think there are that many hassles to bolt in a LT1.

It would be easier to do heads/cam on a L98 to get it to the 320whp range than swap a whole new motor, but the LT1 has better potential all around i feel.

I'll leave it at that. I wouldnt want to take a healthy L98 out for a LT1 either, but if your like me and want performance you'd do it and i kinda feel bad i didnt go that way earlier.

 

As I've said before the LT1 is nothing more then a glorified SBC with reverse cooling and opti-spark.
Same size rotating assembly, save 23* heads.
If you get an LT1 dirt cheap go for it, there's nothing wrong with them.
But heck for $1500 I might sell you my TF heads and cam that also put more then 320rwhp down. At least then you'd get 18/16* degree heads more like the LS1 has.
To each his own.
To me the LT1 is like stroking a 305. Lets face it after you waste all the time and money your going to want a 350 down the road.
Putting in the LT1 is a stop-gap and lets face it down the road you'll want that LSx.

 

anyone worried about the obsolesence factor of the LT1?

The fact it was 5 years in F-bodies and 6 years in Corvettes. Hard to service in years to come ect, stuff like that?

LS1 swap sounds very $$$---I am thinking Supercharge the TPI!
Or Turbo......some day

 

LT1's have a nice aftermarket following. It was in caprices/impala/roadmasters, F-bodies and y-bodies.

So there is a very healthy line of cars that use parts from it, it'll be around for a while.

As for LT1 vs L98 this is what you can do.

Stock LT1 is very comparable to a L98 with vortec heads and a vortec HSR intake. With similar cam profiles they will be very close in terms of powerband.

Vortec heads ~$550, Vortec HSR ~$650. $1200 isn't a bad figure for near 300hp. Add headers, and a cam to match the new build and 350hp at the crank shouldn't be very hard at all.

 

You'll be able to get parts for it for decades to come in any gen engine, BUT in the scheme of things the SBC was around for 30+ years.
The LT1 around for ~6 years.
The LSx has already been around for 12 years with cars already planned to use it in the next 2 years and it shows no signs of slowing down.
So in the grand scheme of things in the future both LT1 aftermarket parts and LSx aftermarket parts will be around, but I bet you will be able to find way more variety of LSx parts.

 

ACTUALLY...the LT1 had special lightweight pistons, and a stronger lighter crank, with stronger rods, than a regular SBC, also had a DRY intake manifold,i have heard tht the stock exhaust manifolds were crap, but i dont know for sure, anyway that would be one of the first thing most people change anyway...and the reverse flow cooling helped it reach the higher compression ration that it had, and cooling the heads first allowed for more spark/timing advance (not sure which, but one of those...) so it is more than just a glorified SBC...as for the opti spark...i have red that it is a piece of crap, and then i have read, it works just fine...all in how you take care of it i guess... I thinkthe LT1 is worth the money...

 

The opti works great, until it gets wet, then it takes a dump.

So make sure that waterpump is in good running order or you'll be sorry.

 

im cosigning

 

This is true...i intend to take very good care of it, by the way..one day putting the distributorless ignition style thing on it...plus i am thinking of changing the firing order, that 4-7 swap has me interested, or the LSx firing order...bu who knows...
but besides the accesory drive (unless you got a corvette set up) it should be a regular 350 swap...

 

So if you were starting from scratch blown moter and a bunch of parts would you go lt1 or ls1??

 

LS would be the answer is money is no option.