I've got an '89 Trans AM with a TPI 305. I've got a 350 from a '76 gmc pickup.... it has vortec heads and a bunch of other sutff that made it put out about 400 hp. In the truck i used an edelbrock performer intake manifold and a holley street avenger carb.

I wanted to know if the TPI intake manifold i have would bolt up to the vortec heads, if not, is there one you'd recommend to replace it?

will I need bigger runners? rocommendations? ...

anything else you think i might need to know before i get started on this?
....i only want to use the TPI if it's going to out perform the carb.... so, i don't want to do anything half ***... i want the best stuff if i've got to replace something.

Thanks :-)

 

The stock manifold is not compatible with vortec cyl heads. You can make the swap work for about 400 bucks. Scoggin Dickey Perf. Parts makes a TPI vortec base manifold specifically designed to work with those heads. You can keep everything else stock. But since you are putting such better heads on there I would seriously consider upgrading the runners to maybe the SLP style. And do some porting of the Plenum and what not to take full advantage of the setup. Hope that helps


As far as "outperforming" the carb, it all depends on how you intend to use the car. Daily driver, with 400 horses and a carb, you are going to be going to the gas station about every other day. Once you go over the 1:1 ratio of cubes to hp you start to lose alot of economy and reliability. Even with the TPI its gonna guzzle gas, but not as bad. EFI is significantly more fuel efficient.

I should add that with that much power some strenghtening of the frame and some solid suspension mods are in order, otherwise you'll just spin the tires for days, and not to mention end up twisting the body.


Will

 

you think it would out perform the carb with just a manifold? ...i'll more than likely upgrade just about all the TPI components i can at some point... but when i first drop in the 350 i want it to be putting out atleast as much power as it was with the carb...otherwise it seems pointless to invest the $$ in the TPI when i have everything for the carb.

 

Its give and take, stock, the TPI is going to throw down loads of torque, but its gonna drop off soon. The long runner design builds torque down low, and hp is pretty steady trough about 4K around there its gonna drop off really fast. Thats the downfall of TPI, nothing to keep it breathing up top. TPI and carb are really different. Carb is good for all around simple power, slap it on and go. But with EFI, its gonna require some tuning, there are sensors and computers involved. Done right theres nothing a carb can do that the TPI can't do better. But its just gonna take some trial and error. Also make sure you get the right manifold. If the motor with the vortecs is off a 70 something, its likely has a flange bolt setup on the heads. Versus centerbolt heads. I do believe this is critical in selecting the right one. THe two are not compatible and you will need to make sure they match up. All f-bodies use centerbolt heads after from the year 87 to present. So check on that just to be safe.

Let me know if I can help

Will

 

so, what can i do to get torque above 4000rpms? ...when i had that engine in the truck it didnt seem to peak till around there... so i don't want to give up the torque i had after 4000.....

 

MiniRam III

 

link? how much $$?

 

Its going to be pricey, but definitely worth it. Try TPIS's website.

Will

 

the TPI setup will NEVER out perform the carb...without some MAJOR $$$ to be thrown at it. thats the reason im switchin my car to a carb. i think the SLP runners are like $300-350. that right there is an intake and some more money left over for a carb! (not to mention the $350-400 ur gonna spend for just a BASE of the TPI for Vortec heads).

if u put that motor in ur car w/ the stock TPI,ur gonna be so mad about how much worse its gonna perform than when it was in the truck w/ a carb on it. do u know the specs on the cam? if its a cam that has a RPM range of say 2,000-5500 or 6,000 the TPI is gonna hold u back BIGTIME stock. u can port,grind,sand,seimese the runners all u want on a TPI motor...its still gonna run outta breath about 5,000 RPMs.

hope this helped u a little

 

This is the intake needed. This is why I will not consider the Vortec heads on my car. With my setup, I am thinking of experimenting with the HSR and I can do it too because I am not limited by the manifold.

The manifold is the problem in our cars. That is why I upgraded to the Superram Intakes and maybe later on the HSR to see if I like it better.

I'd say you need to consider carefully what you want to do. Your options are to go to a carb and lose the benifits of EFI or ditch the Vortecs and get something better that will be more flexible. All depends what you want to do in the future and how you plan to use your car. I am happy with my EFI setup and drive it year round. Carbs may or may not be able to drive year round without resetting something.;