Waking up an LT1

[Last Ride]

Hey all--
I was just wondering if someone could give me some pointers on some things I could do to wake up a 1995 LT1 motor without really tearing into it. The motor I have now only has about 18,000 miles on it, so a rebuilt is (hopefully) a ways down the road. I want to draw some more power out of it, and was wondering what you thought would be a good way to do that. I was thinking heads and a cam, with some full tube headers would do the trick. Then maybe a 52 or 58 mm throttlebody. Eventually, I want to build a low-CR 396 and force feed it with an ATI Procharger, but that will be a ways off. Any suggestions as to what else I could do? What is it going to cost me for a decent head/cam setup? Should I port the factory heads, or go with something else? If something else, what? Any cam suggestions? Thanks for your time, all!

 

[JPLT1]

Put some gears in the back and dont even have to mess with the motor. Put 3.73's in my car and that was the best mod Ive done so far.

 

[LT1Vettepilot]

A few basics

Here are some ideas I've looked at doing to my '96. This is my daily driver, so I was looking for continued dependability, fuel economy, and some more "punch" out of the hole.
52mm Edlebrock throttle body
1.6 roller rockers
LT-4 "Hot cam" kit (I believe this comes with the 1.6 rockers)
Adjustable fuel pressure regulator
Open air box w/ K&N filter
Reprogram on computer ('95 I believe you can just "chip" swap
opened up exhaust system (maintaining stock manifolds, just the pipes and mufflers)

All for about $2000 plus installation.

The only thing I've managed to accomplish is the K&N filter, but I haven't opened the box up yet.

I have a Corvette technician working at my local dealership who has built several high powered vettes which are still daily drivers and very streetable. In fact, one of his cars drove from here (Little Rock AR) to Texas for the Viper Shootout, won the competition, then drove back. Can't beat that kind of performance and daily reliability! For about $5000, he can bring me up to about 400-450HP at the wheels, this included the above mentioned items, and a supercharger with running low PSI. Hope this helps for you.

 

[Preacher]

I have a 95 LT1 Vert 6sp.

Let me preface this by saying:

I haven't raced at the track and have no idea what my true horsepower is.

Mods:

SLP intake, Power Effects exhaust and 4.11 gears and this car is a monster..... fastest car I have ever owned even though my Impalla SS and my Charger both had more brute HP.

 

[bradfordsvettes]

like what was said before try the 3:73 gears it is the best bang for the buck i do this for a living and have yet to have an unhappy customer steve crazy

 

[JPLT1]

bradford, I sent you a PM.

 

[Mako]

like what was said before try the 3:73 gears it is the best bang for the buck i do this for a living and have yet to have an unhappy customer steve crazy

On a low mile beauty like what you have, I'd recommend you stay out of the block for now. There are too many other places you can look at to find better performance without blowing big $.

Gears rock, 3.70's on a 6 speed are fantastic stuff, but you do require a PCM reprogram to have the speedo and odometer work correctly.

I feel 4.10's are "too" much gear for a 6 speed driver, others will (firmly) disagree. 3.40's on an A4 seem to be an excellent fit as well, particularly with the stock converter.

Do the gears first and reprogram the PCM. for them. Drive that around for a while, then when you get greedy for More, improve the engine breathing on the intake and exhaust sides.

Installing 1.6:1 roller rockers is as far into the engine as I can recommend at that point. You should check carefully for spring bind when you do that, as it's a pretty near thing.

A note on throttle bodies:

The intake manifold holes are 52mm in diameter. To fit a 58mm TB requires you to pull and machine the openings to 58mm first.

To make it a little more fun, the holes on the various TBs are not located exactly the same. You have to gasket match to the specific TB you purchase.

Also, for a NA car, 52mm is about as large as you want to go anyways, at least until you stroke or bolt on a blower. 58mm has a reputation for a soggier throttle response on a 350.

CYa!
Mako

 

[vms4evr]

Gears. Like the others said. Put a set of 3.54s in my A4 and what a jump from 2.59 factory gears. Plenty of pulling power, still have good top end. Great mod and bang for the buck.
Graham

 

[Last Ride]

Put some gears in the back and dont even have to mess with the motor. Put 3.73's in my car and that was the best mod Ive done so far.

JPLT1--
Is the RPM on the highway that unbearable with the 3.73's? For automatic cars, I always heard to keep the final first drive ratio under but as close to 10:1 as possible, which would make an A4's ideal match around 3.23 rear axle. I like the idea of 3.73's, but eventually, this will be a cruisng car as well as a street monster, so I don't want the motor to sing in overdrive. Thanks for the tip!

 

[Corvette-Pilot]

like what was said before try the 3:73 gears it is the best bang for the buck i do this for a living and have yet to have an unhappy customer steve crazy

bradfordsvettes

I just sent you a PM.
I also live in MA and want to do the gear swap and need some info from you.

Thanks

 

[vettn94]

GEAR GEAR GEAR !!!!!
Judging from your response I take it you have an automatic.
I replaced the stock 2.59 in my 94 auto with 3.54's and saw my ET drop over 5 tenths and picked up over 5mph in the 1/4 mile.
So far that was the best mod I have done period.
Heads/cam and long tube headers are a great way to go too.
You'll have to ditch the cats with the long tubes. I don't know if you have emissions testing down there in Springfield, if not you won't have any problems.
We have them up here in the Chicago area which is the only reason I don't have long tubes on my 94.

 

[Last Ride]

GEAR GEAR GEAR !!!!!
Judging from your response I take it you have an automatic.
I replaced the stock 2.59 in my 94 auto with 3.54's and saw my ET drop over 5 tenths and picked up over 5mph in the 1/4 mile.
So far that was the best mod I have done period.
Heads/cam and long tube headers are a great way to go too.
You'll have to ditch the cats with the long tubes. I don't know if you have emissions testing down there in Springfield, if not you won't have any problems.
We have them up here in the Chicago area which is the only reason I don't have long tubes on my 94.

I think I will be going with gears pretty soon. When I rebuilt the rear axle about a year and a half ago, the rebuilder just put the 3.08 back in even though I wanted to go with 3.55 or higher. I wanted the car back, so I just let it go. The car has 3.08 right now, and I am thinking of either 3.55 or 3.73. By the way, my car hasn't had cats for a while, but it is not a C4. Who makes longtubes anyway? I want to redo the exhuast, so that will be another project. Thanks for the reply!

 

[rich95]

GEAR GEAR GEAR !!!!!
Judging from your response I take it you have an automatic.
I replaced the stock 2.59 in my 94 auto with 3.54's and saw my ET drop over 5 tenths and picked up over 5mph in the 1/4 mile.
So far that was the best mod I have done period.
Heads/cam and long tube headers are a great way to go too.
You'll have to ditch the cats with the long tubes. I don't know if you have emissions testing down there in Springfield, if not you won't have any problems.
We have them up here in the Chicago area which is the only reason I don't have long tubes on my 94.
_____________________________
94 Convertible LT1/A4
3.54 gear, 2800 stall PI Vigilante, B&B Triflo cat back, LPE Shorty Headers, BPP Vortex Rammer
13.02@105.36mph / 1.78 60'

vettn94,
When you replaced your 2.59 with the 3.54, did you simply replace the gut or did you have to replace the entire carrier? I had heard the if you wanted to move up in gearing, you need to change from a Dana 36 and go to a Dana 44.
rich95

 

[vettn94]

Rich,
You can use up to 3.73's in the Dana 36 but I believe you'll need to change the carrier if you currently have a 2.73 or 2.59 gear . I'm not sure if the 3.08's carrier is compatible for a 3.45 or higher gear, maybe someone else knows.
I bought mine as a complete assembly, just the pumpkin.

My buddy Jeff helped me install it.

 

[-=Jeff=-]

My buddy Jeff helped me install it.

Yeah I did.. but you got to do all the U-joint Bolts if I remember the cussing correctly.. LOL

 

[vettn94]

U-joints suck!!!

 

[vms4evr]

You don't have to change the whole carrier to go from 2.59 to 3.54 or 3.73. They fit in there, tight, but they fit. If you already have the 3.07 (G92 option) then you just need the correct speedo gears. If you go from a 2.59 then you also need the 3-Series VSS. Same Dana 36 carrier wheather you got factory 2.59 or 3.07 gears.
Graham

 

[Corvette-Pilot]

Rich,
You can use up to 3.73's in the Dana 36 but I believe you'll need to change the carrier if you currently have a 2.73 or 2.59 gear . I'm not sure if the 3.08's carrier is compatible for a 3.45 or higher gear, maybe someone else knows.
I bought mine as a complete assembly, just the pumpkin.
My buddy Jeff helped me install it.

Where did you get this setup?
Was there an exchange for the old one?
What did it cost ! !

Now the big one:
How hard was it to swap out !

I would think it would be much easier to swap out than pull it out and have it rebuilt?
All the new parts are nice and clean

What is involved in the removal of the rear end?
I haven't been under there yet to see