more power out of 87 350TPI?

[V]

Motor is a rebuilt 1987 350 TPI, not bored out or anything. Runs great but lacking in the power department. Has the stock 87 roller cam and heads. Only mods are SD tune, shorty edelbrock headers, and aftermarket cat-back. Still has 3" cat converter. A T5 manual transmission is behind it.

I think the motor was rated for 225hp in 1987, and as is now, it dynoed 201hp. So thats about right i figure for a stock setup.

But now we are looking to egt more power out of it. Where should i begin?

The trans is being switch to a LT1 T56 that we already have.

The owner is thinking cam, internals, possibly a stroker kit, upgraded tpi parts, etc... but i dont think the power increase and work involved is worth it when there are other engine options. ie LT1 or LS1. I have a 7k orig mile 96 LT1 from an Impala SS, and i think with a head swap and cam, thatd give us a good power increase right off the bat.(its already set up with a stand alone wiring harness). OR id really like to go LS1 with the parts i have laying around my garage. With just a cam, LT headers, and tuning, thatd be much nicer i think. Only issue there is we'd have to swap the T56 for an LS1 T56 version, which is still feasible though.

whats you opinions?

[JerzLT1]

my LT1 with heads/cam goes 11.53 @ 120 mph/ stock bottom end. if you need an LS1 i still have mine :)

[V]

Personally I'm leaning towards an LS1 setup. I have basically a complete motor once i pick up the block im buying, id just need to put it together.
I have my stock '01 crankshaft, '01 241 heads, an '00 ls1 manifold, extra water pumps, etc etc. A few gaskets and some ARP bolts and i'm set.

Plus, ive been thinking about then doing forged rods and lower compression pistons, a few other upgrades, then 6.0L truck manifolds, a basic single front mount Turbo(~4-5 psi), custom intercooler install and an SD tune.... should be enough power then. If i'm not doing forced induction in my SS i figure i need to do it on something. A turbo LS1 six-speed Monte SS would def be badass.... hmmm. now just to convince the owner....

[Pampered-Z]

The TPI is what kills the engine from making big HP, those long runners and small plenum are great for low end torque but can't make HP.

How far do you want to push the HP? Just dropping in the stock LT1 will gain you 50HP, mild cam like a 305 would put you near 300-310 hp. If you are looking for 375-400 HP then I would go LS1 with a nice cam and heads.

Whatever parts you buy to build the TPI 383 would be the same parts you'd use in the LT1 block. So if you want a 383 build the LT1 383. Your have better heads to start with and an intake that can support the air flow.

Remember to keep some budget for a good set of weld in subframe connects, 3rd gens bodies flex! It it's a T-top car you might want to think cage or some other supports as well.

[V]

Remember to keep some budget for a good set of weld in subframe connects, 3rd gens bodies flex! It it's a T-top car you might want to think cage or some other supports as well.

The only reason its TPI is because thats what i had laying around in 2004 when i started building it. And as you can see, its not a 3rd gen or an fbody even. lol. In the spring, I will have the chance to go through the car again completely to clean up stuff i was never satisfied with in the original build(paint & body, gauges etc).

If i use the LT1, id need good heads since the stockers are the iron ones.
All options would cost about the same due to the number of parts i have. I honestly think an LS1 swap would be the cheapest since i have so much left laying around from my car.

The car is female owned and driven so 400+ hp is not needed, lol. But 350hp is about the lowest i want it to have.


http://photos-f.ak.fbcdn.net/photos-ak-sf2p/v235/219/91/1068600372/n1068600372_59694_7995.jpg

[bubba428]

I'll take that LT1 T56 off your hands if you decide to go LS1

[Pampered-Z]

The car is female owned and driven so 400+ hp is not needed, lol. But 350hp is about the lowest i want it to have.




LOL! I just ASSumed it was an F-body!


For your LT1, You can get just as much HP out of those heads as the Alum versions, just have added weight. A set of stage II heads ( good porting, larger valves ) and a 305 cam should put you in the 350HP range, moving up to a 306 or GM847 cam would put you in the 370-380HP range but at that point you are going to loose some drivablity in the low RMP range, not going to be very smooth driving in traffic, will need to deal with some cam surge. So at the 375 HP range a LS1 with a hotstick and heads would make the same power but be a bit easier to drive on the street.

I'd go LS1, probably a bit easier of a swap as well,

[LTb1ow]

LOL! I just ASSumed it was an F-body!


For your LT1, You can get just as much HP out of those heads as the Alum versions, just have added weight. A set of stage II heads ( good porting, larger valves ) and a 305 cam should put you in the 350HP range, moving up to a 306 or GM847 cam would put you in the 370-380HP range but at that point you are going to loose some drivablity in the low RMP range, not going to be very smooth driving in traffic, will need to deal with some cam surge. So at the 375 HP range a LS1 with a hotstick and heads would make the same power but be a bit easier to drive on the street.

I'd go LS1, probably a bit easier of a swap as well,

Granted the LS1 may be a tad easier to make power, but for the cam that is in my car, its def drives better than you would think. A good tune does wonders to having a larger cam.

Also, wouldn't an LS1 require new K member etc and custom headers or stock ones and custom Y pipe?

[bubba428]

Granted the LS1 may be a tad easier to make power, but for the cam that is in my car, its def drives better than you would think. A good tune does wonders to having a larger cam.

Also, wouldn't an LS1 require new K member etc and custom headers or stock ones and custom Y pipe?

he said easier...not cheaper

[NastyEllEssWon]

i wouldnt think that the monte would use a kmember matt....iirc those montes should use standard pedastal style mounts like for the third gen...if thats the case then the swap becomes easier....not to mention that tons of people have gotten all types of trans' to sit behind the the ls1.




i vote for ls1

[bubba428]

G-body does not have a K member like an F-body does. the engine cradle is welded to the frame. however, it does have multiple bolt holes that allowed the same chassis to carry every engine from BBC, BBO, BB Buick, SBC, SBO, chevy 4.3, buick 3.8. I'd imagine the position for SBC would work with LS1

[WildBillyT]

G-body does not have a K member like an F-body does. the engine cradle is welded to the frame. however, it does have multiple bolt holes that allowed the same chassis to carry every engine from BBC, BBO, BB Buick, SBC, SBO, chevy 4.3, buick 3.8. I'd imagine the position for SBC would work with LS1

Not sure it would- but conversion gen I to LS1 motor mounts would be cheap and easy.

[LTb1ow]

Not sure it would- but conversion gen I to LS1 motor mounts would be cheap and easy.

BUT isn't an LT1 SBC mounts?

[bubba428]

yes...but why would you do a motor swap and NOT change the mounts??? I mean, it just kinda makes sense to me

[LTb1ow]

yes...but why would you do a motor swap and NOT change the mounts??? I mean, it just kinda makes sense to me

No I mean, an LS1 mount is a completely different style than an LT1/SBC mount.

[bubba428]

I know....what i'm saying is, your doing the work anyway... so F it, just go with the motor you choose

[bubba428]

http://www.youtube.com/watch?v=g3C0-btzLHk&feature=related

obviously its possible, and not terribly hard

[GP99GT]

blower

[LTb1ow]

You could get all sorts of crazy hybrid... LT1 intake converted to work on the TPI... a LS1 running it... 8 coils versus dizzy... and then, lots of nitrous.

:)

[S.J.SLEEPER]

damn.... seems like everyones ls1 nuthuggin for once....
yes mr. ls1nuthugger says go ls1.
I have tons of stock ls1 parts pans,mounts,blocks, and alot of stuff would be more than glad to just give you to help you out. and get more room in my shop.

you can bolt a t400/700r4 behind the ls1 with now problem at all.
as for t56 I am sure there is something you can do with that too..

[Teds89IROC]

blower

This

[Tru2Chevy]

I vote 350 TPI - she doesn't need anything nuts, and this setup will provide plenty of low end grunt that a nice street car needs. Toss a little boost in the mix and you negate the downsides of the TPI intake, it flows great when it's pressurized!

LSx motors are great, but everyone and their mother wants to swap 'em these days. Going against the grain is more your style Paul :)

- Justin

[bubba428]

sooooo you selling that T-56........... ;)

[V]

hmmm a forced induction 350TPI... thats a possiblility...

in that case we'd keep the lt1 T56...

so now a blower or turbo...hmmmm

[JerzLT1]

turbos are a bitch to tune

[GP99GT]

turbos are a bitch to tune

not really...you just have to know what youre doing

blower is probably easier and more straightforward but a turbo will make more powar