My 87 GTA convertible has a stock 305 TPI setup at the moment.

I got a 383 V8 with holley 650 carb + holley intake. The question is now if I should put the holley carburator together with the 383 in my convertible or stay "more" original with a 350 TPI setup + 383?

Martin

 

TPI 383 will be awesome but you need the right cam and the right rear end gears to make it work. it will be awesome at the bottom end but because of the TPI intake, it will die at higher RPM. but if you go carb, you can get an intake to make it light up at high RPM, which is pretty ghey for the street. what cam you got in your 383 now?

 

Why not use a Stealth Ram manifold? Far as I know, it will work with all the TPI stuff (injectors, distributor, electronics, sensors, etc), just need to buy the HSR manifold and its matching fuel rail set. It would work very well on a street/strip 383.

If you go carb, forget the 650 - start with a 750 Holley. Its a better match for a big small block like a 383.

 

i did a carb when i bilt one for a t/a i used to have and i always wished i kept the tpi

 

if this is going to be any kind of street car stick with tpi. Going with a carb will result in much worse mileage, if it's a strip car, go with the carb you will make more power

 

I will mainly use my GTA vert for the open street, summer cruising, not much racing. My cam is a 3 1/4 Comp 242 Cam from Hawaii Racing.

Concerning the difference 305 to 350 stock TPI setup – which parts should I change / upgrade – ECM module?

Stealth ram is an interesting point of view … I have to do some research on the advantages on that solution.

Thanks for your help guys!

 

Your answer all depends on what youa re going to do with the car. I agree with the post above that you HAVE to have the correct camshaft to go with what you decide to use.

Drag Race / minimal street = Go with Carb and cam capable of using the entire RPM range of the 383. I agree start with atleast a 750CFM

Road Course car / street = If you are going to run a "stock" class (SCCA) then I would stick with the TPI setup and a cam designed for low RPM torque and mid RPM range power. You will want to go with a camshaft that peaks around 5K do to the TPI running out of air. The ideal setup would be to go with a aftermarket intake that is capable of flowing to 6500 RPM and a cam to match. This will take a mini ram or Super Ram or even a reworked LT-1 will work.

Street Car no racing = Same as road course car!

The 305 and 350 TPI (minus INJ) were all the same. You will have change the runners and do some upper intake porting along with replacing or porting the lower to get it to flow at higher RPM,s. Keep in mind the TPI was original designed for a truck motor with all low RPM torque and not high RPM performance.

I went with the SR on my 383. This allowed me to get decent gas mileage and good drivability on the street along with being able to have usable RPM to 7K plus. I track the car and the FI also helps eliminate fuel starvation in corners that is a problem with carbs. You will have to decide what you want to do with the car and use what fits your needs.

Just my 2 cents!!

 

It sounds like you already have the engine, otherwise I would not recommend a 383 for a street car and TPI. TPI engines already make tremendous torque, so there's no need for a 383 engine unless you pair it with a short runner intake. Since the car is already TPI and you want a street cruiser I would very highly recommend you keep it TPI to avoid the hassle of converting it to carb and ruining the car. However, with a camshaft that large you will need to find someone local to you to do the custom computer tuning that will be required.

 

Actually I was hoping that you would recommend to keep the TPI setup. That is also what 2 people in Europe told me. Besides I prefer the "original" look from the visual perspective, since it is also a rare GTA convertible in Europe.

Actually I am not 100 % sure if it is a 383. The previous owner said he thinks it is a 383, but he sold it as a 350 with this specifications: 350 crate engine, ~ 10000 miles, 3 1/4 Comp 242 Cam from Hawaii Racing, Holley 650cfm, Super Comp Holley Strip Dominator intake. The engine runs great, he just sold it because he wanted to buy a Big block for his Chevy Nova.

You say I should change the cam to something supporting lower RPM torque?

Thanks for the TPI recommendations, please keep advising!

 

When I change from 5,0 l TPI to 383er TPI stealth ram, should I change to the parts from the 350 TPI setup: injectors + knocksensor + ESC module + ECM module + PROM? Or are there 383 specific parts?

 

TPI looks so good. Why mess with something so purty?

84 - non 350/383 specific parts, KS, ESC module, ECM, Prom. You'll have to get the ECM programmed though for a 383.