I want to poll what you guys think I should do with my 1985 vette, it has the 350 TPI, completely rebuilt with a mild cam, I just got it running great (except for an oil leak from the back of the intake I think) it still doesn't have enough power for me, I have the 4+3 manual trans and this engine doesn't pull to hard, it is really expensive to modify a TPI and I can't afford to anytime in the near future, a swap to carburation would be affordable with a used intake and stuff and this would give me an opportunity to get rid of emissions and get better mpg (hopefully). What do you guys think? I think a carb will pull more power and I have never had any driveability issues in my previous carbed cars. Please give me your imput. Thanks.

 

I would keep and modify the TPI in there now, in the long run, you get more consistant MPG, better cold weather drivablity, and once it is tuned right, nothing else needs to be done until the next mod

 

keep the TPI... no question about it. They are GREAT motors and you can get a ton of power out of them.

Charlie

 

See sig.

I was running right next to bolt on LT1's with my setup, Stock heads and TPI unit. Unless you cound new gaskets and seals to be not stock. (Always have to put the disclaimer in there )

 

I too would keep the TPI. I know if you work around its power range and get the combo right it can be fast. What do you want to use the car for? Cruising or racing? Is fuel mileage important to you? What is your 1/4 mile goal? Also remember that the 4+3 trans needs the ecm to operate the overdrive unit. It may also need various sensors from the engine (tps).

You should go to www.thirdgen.org and look in the message boards over there and see what us F-body guys can do to L98's and make them run. There are many cheap and effective mods you can make to the motor to get power and torque.

 

hey mike, dont the L98s only have alum. heads? his are iron. yeah john, keep the tpi until you want to go fast, then ditch that piece and either buy an expensive replacement mannifold/injectors setup and get custom tuning(read:more money you dont have ) or keep the tpi setup for when you DO have the money to make it fast, and just put on a carb for now. you already knew my opinion on this though.

now, I know all you guys are goin to be upset to see this, but also consider he wont ever drive it in the cold or bad weather. he's got a jeep for that. also, why not come up w/a list of needed mods to create a package that would give him a noticeable gain in HP and torque and also put your approx. price. now, fuel mileage is also somewhat of an issue for him cause he does ALOT of driving. but if my Iroc gets 16 MPG now, I think his very mild vette w/a carb on it can get a little better even. maybe like 18 or so w/the right carb/cam selection.

 

I may have a few things laying around the garage that may help with a little power. I know I have a air foil. All my stuff was for a Camaro.
Anyone need a set of Headman headers with the y pipe and hi flow cat. I picked them up a few weeks ago and changed my mind and am going with the Hooker LT's.

 

He should have the iron heads....Aluminum wasn't until 87.

 

Thanks for the input thus far guys. I am still undecided. I have law school finals all week but next week I want to start working on the vette. The reasons I am thinking of swapping are: I have an oil leak from the rear top of my engine and I think it is the intake anytime I do 3+ hours work to my car I'd like to pick up some performance.
TPI: Cold air induction = $300
Airfoil = $40
Stealth ram intake = $$$$
New fuel rails = $150
Custom tuning = $$$$
The sad thing is the engine was just rebuilt professionally (yet it leaks oil), the injectors, maf sensor, knock sensor, are all brand new.
Carburated: Intake $115
Carb: $340
HEI distributor: $150
Inline fuel pump: $80
The carb is a more economic choice for now, I don't know which will be better in the future. Now that I have seen real prices, I might keep the TPI, put headers with true duals, no cats, bullet mufflers, and strip off the air pump, make my own cold air intake. This option will cost me the same as the intake/carb selection. My thoughts now go to How much power will this make?
My L98 does have iron heads, higher compression due to rebuild/ decked heads and a slightly larger cam.
I will spend some more time thinking about this since my budget is my main concern right now, my need for speed takes over me sometime.
Please give me some more suggestions on what you guys think, I guess the header/no emissions option is number 3.

 

If you rewire the stock fuel pump in the tank to come on with the ign. you can get a mallory fuel pressure regulator that will bring it down to 7-9psi.

As for exhaust, I had true duals, 3 " all the way to the back with stock LT1 mufflers. Sounded better than anything aftermarket out there and made a big power improvement, even if it was a little overkill.

The stealth ram intake is only $655 once you get all the small stuff needed to put it in. Theres an article in a recent GMHTP magazine. Only thing is i don't think it'd clear your hood

If money is of a big concern look around for TPI parts on Ebay or other places. Used stuff is the best way to go when you're on a budget.

 

john, heres some prices from jeggs. dont know where you got your estimations from.

torquer intake 350-5001===$93.99
holley 600 cfm carb 510-0-80457S===$214.99
or
holley 750 cfm carb 510-0-80508S===$239.99
mallory return style reg. 650-4309===$74.99 (your pump is fine, Im using the stock tpi pump)
Accell distributor, cap, rotor, with coil 110-59107C $135.99

gaskets, around $40
intake bolts, return spring, bracket for throttle cable, maybe $50

I think thats it.

chris

 

Thanks IROCSS85, the prices I got were estimates from summit, I just chose different brand parts. I like your estimates better. I guess I still have time to think about it, I should finish finals this week, next week I need to find/fix the oil leak, fix the overdrive unit, oh and a few parts should be arriving this week to tweek the suspension on the vette (you know how I like a good handling sports car)
Parts coming in right now are: energy suspension bushings all around (red since my car is black) Bilstein shocks, shifter kit, etc.