Advise for a LT1 build

[Scott A.]

I picked up a 97 Z28 LT1 A4 that needed work over the summer for cheap, fixed it, and have been driving it the last few months. Never owned a 4th gen F-body, it's kinda grown on me and its a fun car in the summer. The car only has 111k on it, and is pretty clean and runs good now.

Lately I've been considering dropping the motor and addressing a few more things over the winter. I'd like to do a mild build on it if I can do it for around the $1500 range. It will still be a driver, but is it realistic to get into the 375-400HP range for around $1500 and keep it a driver (not on spray either)? I was considering these mods:

1. LT4 hot cam
2. 2500rpm stall
3. Head port and polish (I have a friend that's done this before and he said would do this for me)
4. Long tube headers & y-pipe
5. Cold air intake
6. Tune
7. Valve springs & lifters

The car is all stock right now, and has the 3.42 limited slip already in it. I would probably do the re-ring kit unless I found more problems while I was in there. I've already heard the 'sell the LT1 and get the LS1' from a friend, not really interested in that either if I can get into the 375-400HP range on a budget, this would basically be just a fun daily driver.

What do you think about the mods and the budget?

 

[buddy]

I had a 94 ta lt1 ran 13.6 with just a cai and catback. Car was fun to drive and sounded great. Only cost $2000 was the best part.

 

[buddy]

I had 3.23 gears though. With 3.42's, I'm guessing yours is a stick.

 

[novaderrik]

if the LT4 heads aren't in your budget, then get the iron heads from a Caprice: they are heavier, but they flow better than the aluminum LT1 heads. they are what the vortec truck heads were modeled after.
go with the HOT cam kit, not just the cam. don't forget the LT4 knock module thingie (forget what it's called) so the roller lifters don't screw with the knock sensors.
open up the stock air box, that should get you as much flow as any aftermarket cold air kit.
long tube headers, cat delete, and Flowmaster cat back kit really wake up a stock LT1 and would be practically necessary with the better heads and bigger cam.
get the LT1 edit software to tweak the tune on the fly with a laptop. there might even be smartphone apps for this now, so look into that, too.

after all that, it's time to shed some weight from the car, and those cars have a LOT of extra mass to them that can be taken out.

 

[TurboBob]

if you do the heads and cam, upgrade the oil pump and replace the rod bearings. The higher RPMs that the cam swap will run has the reputation for hurting the stock rod bearings.

I'm not sure about the iron head flow vs the aluminums, I heard the opposite.

Otherwise, I always liked the LT1's I've owned.

Of course, I put a turbo on my Impala, that makes them really fun....

Bob

 

[Scott A.]

The car is an automatic, I forgot the previous owner already put a flowmaster cat back on it, and it feels like the shift points may have been tweaked, it seems to shift really hard.

I haven't heard that about the iron heads either. If I can get the aluminum heads ported and polished would that be a better route? Also, what all do you have to do to open up the stock air box?

 

[buddy]

If it's auto and the shifter says prnd21 then you have 3.23's. If it says prnd then they're 2.73's. 3.42 was manual only.

 

[Scott A.]

The 3.42 number came from the RPO codes I checked when I bought the car. Maybe I misread it, I'll double check it tonight. If its 3.23's I'll probably want to change that as well.

 

[jimmymack87gn]

3.42 ratio would be GU6.

Posted from the TurboBuick.Com mobile app

 

[Scott A.]

My bad, RPO codes were actually GU5 and G80, making it a 3.23.

 

[jimmymack87gn]

Although frowned upon the LT1 can be built to run well. A friend of mine had a high mileage (200k) z28, ring n bearing freshen up, home ported heads, zz3 camshaft, precision 2800 stall and a hypertech chip (thats right, no custom tune) and ran 12.47 at 109.

Posted from the TurboBuick.Com mobile app

 

[Scott A.]

That's what I was basically looking for, mid 12's would be more than enough for how I plan to use the car.

 

[novaderrik]

if you do the heads and cam, upgrade the oil pump and replace the rod bearings. The higher RPMs that the cam swap will run has the reputation for hurting the stock rod bearings.

I'm not sure about the iron head flow vs the aluminums, I heard the opposite.

Otherwise, I always liked the LT1's I've owned.

Of course, I put a turbo on my Impala, that makes them really fun....

Bob

the oil pump should be fine- it's actually a higher output upgrade from a regular small block with a bigger pickup tube diameter. and besides, the small block oil system had a proven almost 40 year track record of dependabilty behind it by the time the LT1 came around..

 

[Wahoo]

Sell it and build an LS1 lol, sry but a stock LS1 runs 13s flat, even 12's stock, it would be cheaper in the long run. Get a truck or van LQ4 6.0 and swap it in.

 

[usetaboost]

I had a 93 lt1 trans am with a 3.23 posi rear. Fun car during the summer and I loved the fact that it was a leather option car and a hardtop. I gut the stock airbox and removed the stock silencer and plugged the hole. DId plugs and wires on it and busted the converter out. Car run great after that and would turn the tires easy. Never got a chance to do anymore to it since we ended up selling it, which I regret. If it was me I'd pull the motor and freshen the bottom end. Heads are your choice but I think you could get close to 350hp without doing anything to them. LIke mentioned earlier these cars have restricted intake and exhaust so you get that opened up and it should be a world of difference. A lot has changed since so I'm sure there's something better than an lt4 cam that would be better all around although I'm sure they can be had fairly cheap. Do some research. Just don't skimp on the exhaust. Let that sucka breathe!