Okay guys, I have a bone stock L98 w/ 137 xxx kms on the clock. I definitely want around 400 rwhp.
I plan on taking in to the track occasionally but mostly just a street thumper. So my engine is running real strong right now, no leaks of any sort and does not drink the oil.
Could you guys possibly help me out with a good combination of heads, cam, rods, rockers, and all that stuff. Or should I just go to a shop and get quoted on a build. I do kind of want to keep this build under $8 000 cnd.
Would my stock 700R4 handle the power? Or would it need a build up as well.
Thanks again!

 

So 500 FWHP. Out of a 383.

Keeping TPI?

Set aside about $2k for a TH700 build-up and torque converter.

Now you've got $6k. $3k for the shortblock parts & build, $2k for heads, $500 for cam/valvetrain, you're down to $500 for induction.

 

Nah, going stealth ram.
I just really need help on cam selection and heads and all those items.
Honestly engine rebuilders in Edmonton are thieves. They want 15000 for a 350 rebuild.
So this would be a sweet father son project at home during the winter.
Could you possibly help me out with these selections?
Thanks!

 

So, you are staying with TPI. . .

Heads: A good budget choice would be GM Fast Burns. They are Vortec style, so if you go with them, get the Vortec Stealth Ram.

A better choice would be AFR's, probably the 195cc intake port version. You might go bigger, definitely if going carb, but the HSR may not be able to handle much more than the 195's.

For the cam, absolutely keep it roller lifter. People seem to be doing well with the Comp XFI series. Perhaps something in the 280 range.

The 400 RWHP goal may be a little tough to obtain. But, gotta try! Would be easier with more displacement, but. . .

Nothing more worthy than a father/son project. Keep us posted!

 

Haha sorry guess I am sticking with tpi. Ya, I don't really want to lose the reliability and have to change all the stuff to go carbd.
Alright alright. So should I possibly bore it .30 and stroke it? I've heard that 383s it is easy to make 400+ rwhp. . .

OH quick question.
I noticed that guy is selling a 355 here:
https://www.thirdgen.org/forums/engi...sbc-motor.html

And to me it's sounding like a damn good engine.
Ditch the intake and long tubes and throw a stealth ram and some hooker shorties on her. He says I could possibly see 425hp with that setup at the wheels.
Would that be a good choice for $2000?
I know I'd have to build up my 700R4 and possibly a torque converter.
This is just one hell of a deal.
Its only been fired and no miles whatsoever.

Thanks again!

 

Those horsepower #'s at the flywheel, yes. Rear wheels - highly unlikely.

And, it's 0.030"-over, not 0.30"-over.

 

Oh sorry about the mistake.
Really? Damn, so 425 at the crank would be 350 at the wheels?
How can I get to 425 at the wheels?

 

Drivetrain loss is typically 20-25% vs. gross flywheel HP output. Crate engines, engine component power level claims, etc., are all gross flywheel HP.

500 gross flywheel HP with 20% powertrain loss would equal 400 rear wheel horsepower.

Most 500 gross flywheel sea level horsepower Gen I 383's are not very street-friendly.

Back on the topic of heads - I have a racing bud who has a '57 Nomad 383. For years he's run Dart iron heads (the really old ones, I believe they were the original Sportsmans but professionally ported), Brodix single plain intake, not sure of the cam but shifts at 6800 RPMs, 4500 stall in a TH350, and 5.13 gears. When it was freshened up a couple of years ago the builder said it was a 500 HP sea level engine. It's been a little frustrating because his 4100 lb car has always been a few tenths quicker than my 3900 lb car w/396. I was catching up to him this year, then last month he went and put AFR 195 heads on it (not sure if race ported, CNC ported, or what) - now he's running 4 tenths quicker than before!

 

Make 560 at the crank.

 

Wow that's crazy. Heads make worlds of difference huh. Well how could i produce 560 at the crank. Or even just 500 would suffice? I plan on changing my gearing to 3.73s in the rear too.

 

if your trying to make that much power ditch the tpi...i have the stealth ram you wont be sorry....as far as head i am runnin dart platinum series 200cc intake. id go with something in the 230-240 duration on the cam...lift really depends on what heads you go with. like everyone is saying figure something out for a tranny..no one has mention the little weakling 7.5 our cars come with, theres no way it'll last. dont forget to get some good subframe connectors or ya might twist the thing in half if ya get to that power level.... I hope your into burnin your own chips cause it'll take some time to get it right.....BUT I SAY GO FOR IT!!!!

 

Are you planning on putting a roll bar in the car? With that much power, you're going to be mighty close to needing one in order to run at a sanctioned track.

 

Ahh nope. Just planned on taking her to the quarter a few times. Not much into racing just cruising around and such. But this has been helpful, thanks guys.
If you want to drop some specific parts down you can (part #'s and such)
Thanks.

 

I searched for HP to ET calculators, came up with estimates of 11.87 with 425 RWHP and 3600 pounds. Sounds a little slow to me, but if accurate, you wouldn't need a bar. Helmet, of course.

I'd also plan on a driveshaft loop. A simple piece to install for a good bit more safety.

 

Wow! That's damn quick compared to now.
So would the FIRST tpi system be a better choice to getting to 425rwhp.
Lets say I wasn't on a budget.
What would you all suggest then?

 

stangski09, only way your going to get 425 to the ground with a 383 is either a supercharger, turbo or nitrous. 425 like already mentioned is very achievable at the crank. A manual tranny has slightly less parasitic loss then automatics also. If you want to stay naturally aspirated and still want to aim for the 425 number, you may want to look at getting a Dart 434 shortblock. That will get you very close and may be achievable on motor alone, don't quote me but I'm confident it could.

 

Or a LS-type swap. Stroked 6.0l, a little cam, good exhaust - you're flyin', baby!

 

But you have to change the whole harness and everything for an lsx dont you. . ?

 

It's a cost/benefit thing. Even with the extra work of the install, the ratio is still very favorable.

 

I'd much rather stay old school. People expect a lsx to go fast and all but they definitely do not expect a tpi to walk on an lsx. And if I built this 400 rwhp beauty it would not only look better then a 2002 trans am but it would stomp it at any given time.
I like the choppy idles and the roar she gives when she jumps off the line. Not to mention the unlimited torque that you have waiting for you. I think that i'll do a 383 build with a stealth ram and a big cam and a 3100 stall in a probuilt transmission with 3.42s in the rear and maybe ill purchase a vortech polished supercharger as well to give it that extra power.
Yes it will be a $15 000 build. .
But definitely worth it.
What do you say guys? Sound good or what

 

Stangski09, if you're really going to do thisI went through the same exact thing you are going through right now, however I went 5 speed instead of putting an automatic back in.

I've already ditched the first 383 I had built (was a 8.7:1 motor) and instead built another this winter (a 10:1) so that by the time i do put a supercharger back on I should be at the 500rwhp goal I originally set out for. Careful, building gets addictive

 

I know it's tough deciding. I personally do not really want to add a supercharger, because they are 5 grand alone. Or would you guys suggest incorporating a supercharger into this?

 

Are you dead set on keeping the auto? A manual would be much easier to achieve your goal and would drive MUCH better. There are guys making right at 400rwhp on a stock bottom end L98. I am still trying to get the build details of a local guy making around 420rwhp with a stock bottom end L98. Both of those motors are still naturally aspirated as well. Another benefit to running a t56 or capable manual is that you can run the best exhaust you can get. Long tubes are the best you can get and you can run a proper y pipe instead of the not-so-great ones that come with ALL shorties. I have a set of Dougs long tubes that ran me a little over 500 shipped from jegs. They are a copy of the Hooker 2210 with a better coating and $200 something less. My y pipe will be custom built for my car using a Flowmaster merge collector that has helped make over 500rwhp on a heads and cam 346 bottom end LS1. No need for low hanging or crappy sounding duals here.

If I were to build a 383, I wouldn't be happy unless it was making somewhere north of 450rwhp. And for a 355 I wouldn't be happy if it made under 400-415rwhp.

The problem people run into is that they don't go extreme enough. They buy these great heads (AFR or trick flow) and don't really push the limits. They also stick with a long tube runner setup "to keep the bottom end power" and that's really not needed. Go a bit more extreme on the cam and I bet we start seeing a LOT of really fast 3rd gens instead of the 12 second under performing 383s we see now.

 

Honestly, I was just going to get it professionally rebuilt with corvette servos and all that. But I guess a T-56 would be around the same price. I have no clue on how to swap transmissions at all. . .
I drive my auto using 1 - 2- D - OD. It's much more fun then just driving in OD but I guess a standard would be hella more fun. And like the guy said above you lose less power in a standard.
So what do you suggest?

 

I myself LOVE the T56. This is my third T56 swap. One went into my old 94 z28, one went into my friend's 2000 z28 and now the t56 from my 94 is going into my 91 trans am. The swap is not too bad at all as long as you take your time researching EVERYTHING you need first. Make as many lists as you possibly can and buy it all before you start. There's a t56 swap thread in the transmission section that has been a GREAT help to me thus far.

Further, I would suggest doing the swap before you build the engine. That way you take away as many chances for hidden bugs as possible. So, collect the parts for the t56 swap, also pick up your long tubes and off road y pipe (there is ZERO reason to run emissions unless the inspection stations around you will not pass you at all) parts. Put the headers in at the same time as the t56 (WAAAAY easier to do) and then drive the car like that.

Next up I would suggest picking up the intake you would like to later run and install it. This will get those bugs worked out as well. I would also take this time to look into a MegaSquirt ecu setup. Get used to tuning a mildly modded engine and you will get this under control much easier later on. Plus with the new exhaust, new intake and a good tune, you will pick up quite a nice chunk of power that will tide you over until you get the new engine built. It might also keep you from going overboard on the new one.

I suggest it all in this order because I have found for me a systematic approach like that keeps you out of trouble, keeps the costs down, keeps you happy since the car isn't down as long, and cuts down on possible instals gremlins that ALWAYS come up with stuff like this.

 

Wow, that sounds like a really really good plan. Thanks for that.
So if I threw the HSR on my stock tpi (nonvortec heads) which heads would I later have to through on my engine?
Longtubes and an offroad ypipe? Which headers and ypipe do you suggest

 

Future heads really just depend on what you do engine wise. I however have NOT seen all that great of results from a set of vortec style heads. Certainly MUCH better options out there. For the money I like Trick Flow and Dart stuff but I have experience with neither. I would talk to a reputable builder in the area and see what can be drawn up. Another good place to go for information would be Advanced Inductions. Look them up on google. They turn out some NASTY SBC cars with stock valve location. They will get you setup nicely.

For the long tubes I would suggest coated Doug's headers like I have. They are the exact same as Hooker 2210s but MUCH cheaper and WAY better coating. I also bought the Flowmaster Merge collector from jegs as well. It is the best y merge you can get. The one I got is a dual 3 inch inlet to a 4 inch outlet that I will have necked down to 3 inch for my catback. Finally I bought a pair of Hedman S extensions in 3 inch. With some work they should work well to finish up the y pipe. A competent exhaust shop should be able to get you fixed up.

 

Sweet advice dude.
Thanks a lot eh.
How do you like your t/a?

 

It's not too bad. Liked it enough to buy it twice after I sold it for a 4th gen. Sold it to a friend who was going to repaint it and ls1/t56 swap it. After I got fed up with trying to fix the pos I bought, he sold it back to me. So far I have owned it a year this time around, and owned it for almost 6 the last time. Haven't gotten to drive it yet since I got it back but should be driving again soon.

 

Is it a GTA? So how do you like the 6 speed?

 

Nah, its just a regular Trans Am. I didn't have a whole lot of choice but there's no reason for me to get a GTA because I have already replaced everything that made it a GTA anyway except for the badges.

The 6 speed is great, I just haven't driven this car with it yet. Driven many others though.

 

Sweet deal. Pretty sure I'll do that swap too, whenever I can gather up 3500$. .

 

For 3500 bux you CAN'T ignore the Tremec TKO's. I run a TKO600 and although its a 5spd vs the 6spd T56's I can throw a alot more power and torque at my tranny. I paid about 2100 for a brand new TKO600

 

No way you need even close to $3500 for a t56 swap. I have less than 2k in mine and that includes a brand new Spec Stage 3 clutch. You don't need that much of a clutch until you build the new engine so just buy a stock replacement one of your choice.

 

I was talking canadian dollars. Well torque arm and tranny mount.
Would it fit into my console?
Well it's starting to part now so maybe when I do the swap I should try fitting a 4th gen console in. P.s- is that tough work?

 

Ah, that makes sense then.

It will fit your console and one guy even got it to fit into the stock automatic center section. On the other hand I have an ls1 console that I'm putting in. It needs a few minor mods but it fit right in place.

When you look at consoles, I suggest you get a 97+ console since its the best looking one and most usable as well.

 

Thanks for the advice buddy!

 

No problem really. I just want to start seeing these cars built more "correctly". Meaning stepping outside of the boundaries that people think exist and apply some of the ideas that 4th gen owners do that actually make their car perform to the level of money invested. Meaning, bigger cams, proper intakes and heads, proper computer controls, etc. I bet when people start doing that and stop building tiny cammed 305s, we will start seeing our cars perform like they should.

 

How would I get my ecu to perform properly with these swaps?

 

I would suggest buying a Megasquirt instead. No proms to burn or anything. Just tune it as you drive like a new car has. Plus it has a lot more features too that could come in handy at some point.

Not sure what ecu is in your car, but there is a Megasquirt that plugs right to certain 3rd gens now Something to look into especially since its around the same price as buying the prom burning equipment for the stock setup.

 

Wow, sounds awesome.

 

I did this with my last engine. I orginally had a 11.5:1 327 in my camaro with tpi. When the valve seats let go on that one I built a 383 with dart Iron eagle 195 cc int runners and 68cc com chambers. She had a high lift cam with a 114 degree lda. this yielded a compression ratio of about 10.5:1 with hypereutectic dish top pistons.

I was running 36 pph fuel injectors and a chip from tpichips.com with a completely stock base, runners, plenum. I did port match the base to the heads and the runners to the base and plenum. I also installed a dual 58 mm throttle body from bbk. we installed the cam with a 6 degree advance. we were never able to get more than 350 horsepower out of it but she made close to 500 lb ft of torque at 2800 rpm (flywheel of course).

Horsepower is just a higher rpm torque peak. Unless your primary use is going to be drag/road racing, you can build your engine to make torque at lower rpm very easily with very little modification to the stock tpi. This configuration suits its much better to street driving as it improves gas mileage is VERY fun. I wouldn't go with as much compression and buy better pistons (SRP,etc) if I had it to do over. I could run 13.10ish at a good drag strip with the stock automatic trans/2.73 gears/street tires and the top speed was 175 mph on a good stretch of road.

 

First I want to say that this is nothing against you at all. That said, this is exactly what I was talking about in one of my posts above. A 383 that ran low 13s is not very fast at all. Properly built that motor should be running low 11s at over 120. Not 10mph (I am guessing) and 2 seconds slower.

Low end torque is focused on WAY too much on this board and I am not sure why. A v8 by definition will make plenty of torque to keep these cars from being dogs just driving around and trust me, having 500ftlbs under 3000 rpms does nothing to help you in a race unless you are racing a VERY short distance. Focus on making more power and less low end and your car will be much faster. If I was building your engine it would have had closer to 11:1 compression, Dart track 1 210 (or bigger) heads and a very large cam ground to suit the flow of the heads along with a good intake manifold (stealth ram or converted single plane). My goal would be nothing under 450rwhp and I wouldn't stop until I made more than that.

 

You do have a very good point here. The primary difference between our plans of attack was the end goal (mine being street use and yours leaning more heavily towards traditional road/drag racing output). I wasn't trying to make alot of high rpm horsepower because it would be a waste of time as my average operating rpm was not any higher than 3000 rpm. I also did not want to step up in gearing from the 2.73s that I had in it already. There is no quality gasoline around here as 91 is considered "premium". That coupled with the elevation actually made my compression ratio too aggressive. The gasoline here won't support an aggressively cammed 383 with 10.5:1 let alone 11:1 (not with tall gearing anyway).

If I wanted power above 3000 rpm then your suggestion would have been pretty close to what I would have went with. I would have probably run a single plane intake manifold like a accel proram with a 1200 cfm throttle body, 210 cc intake runners, and a camshaft with lower lda (like 110). Probably had my 700r4 replaced with a built 3000rpm stall th-400 and 3.73 or higher locking rear end.

This however was not my goal. I don't personally enjoy drag racing as I grew up street racing on country back roads in mississippi. I know the mods gonna slam me for this but we didnt race at speeds any lower than 100 mph so the common high rpm and low gearing was pretty worthless.
Plus growing up in an engine building family I was sooooo tired of building 6000 rpm 4.56 geared dragsters and wanted to try something different.
You probably wouldn't beleive how many people have that same exact setup you specified.

I'm not trying to dissude OP from what he wants to do, nor am I trying to torpedo what you are saying. I'm merely offering another perspective and application for your consideration.

 

Lets give the original poster something that we haven't mentioned yet. You can have ASSLOADS of power outta a well built 383 but it doesn't mean jack if you can't keep it planted to the road. My last supercharged 383 posted a high 13 second 1/4 run because I baked the tires almost completely through 3rd gear. Traction is a key ingredient on the street and track.

 

Very very true.

 

Here's what I'm doing. It will cost me around 6 grand--15 grand sounds way too high--who the heck are you getting your parts from? The 6 grand I'll be paying includes labor and the TPIS mini ram. Use your current roller block--Callies forged crank--forged rods--11.0:1 forged pistons--Dart 200 heads--TPIS Mini Ram--TPIS custom chip (call them and tell them your engine specs, and they'll make a chip for you) to make it run--30 lb. injectors--TPIS ZZX roller cam--hooker long tube headers--3 inch y pipe and cat delete pipe--3 inch exhaust back to magnaflow ss muffler--dual ss round tips breathin' out the back. This setup should get you close to 500 crank horsepower and plenty of horsepower to your rear wheels. Definitely get subframe connectors and build up your tranny (unless you do a t-56 swap). If you're not happy with the power this engine will make, spray the beast.

 

Very good points. I just see things through a different light than you. However, with an engine like I described it can still be very streetable and even get decent gas mileage if tuned right and paired with a t56 because its got a crazy over gear. It will take while to get right but when its right, its great.

 

How certain are you about that setup? I like the sounds of just building up a 350 to 400 rwhp. Is that what youre running right now?

 

I Think I may have the perfect answer for you. How about a l98 stroked to a 383, internally balanced with a comp cams xfi 230/236 .576/.570 edlebrock etec 200 (vortec style) heads, Vortec HSR ported to match heads, roller 1.6 rockers, and a COMPLETE t56 swap. This setup made a best of 417 rwhp and has brushed the 11's na on drag radials. I am currently selling this setup to make room for my efi 496 bbc/ 4l80e combo. If you are at all interested or have any questions p.m me. The car is still running and I would be glad to get you a video or maybe some seat time if it can be arranged.