Hallo!
Can anybody tell me if stock 305tbi heads can support up to 250-280hp if not what is the cheapest way to make it works.
I have order a new tbi that flows 580cfm and a new edelbrock performer intake to my other mods.
Thanks!!

 

No.

The easiest way would be to get a set of heads from TPI car, and port them. No way the swirl-port TBI heads will support that kind of flow.

You'd also need an exhaust from the heads all the way to the street, including a set of headers for some other car besides a TBI car. The ones for a TPI car would be a much better choice, plus the catalytic converter and the "cat-back" exhaust for the same kind of car. And a cam; the one in the TBI motors is the weakest cam Chevrolet ever made. People say the stock LT1 cam (93-97 Z28, Vette, & Trans Am) is a good upgrade.

 

OK!
I have done all mods exept the heads,do you think the tpi heads will fit my hooker headders?
And are the stock tpi heads any good without porting them.
Thanks!
Anders

 

Forget to tell you the specs for my cam:206 on the intake,and 212 on the exhaust.It has a valve lift of .480 on the intake,and .488 on the exhaust.It has a lobe seperation angle of 112.

 

How easy is it to get used heads from a TPI car in Sweden? I would think it would be difficult to find them. If it is then you could also check out aftermarket heads. Many of them flow as good as ported TPI heads without having to do any porting. But over here in the states it is a lot cheaper usually to get stock heads and port them.

As far as not porting them, look at the ZZ4 motor. Those are alluminum L98(TPI) heads and that motor makes over 300 hp. Granted it has a better exhaust port than the iron heads I would think you could still make close to 300 hp with stock unported iron TPI heads. That's just my opinion though.

 

That is a LOT of cam for a 305. I'd cool it down a couple steps unless it is just for the drags.

Any carbed 305 heads work great too, if you can find a set. Then follow the instructions at the end of my sig.

 

OK!
I have found a pair of tpi heads from 87 at the junkyard,will they be ok to my car that has a roller cam,and does anybody have the stock valve specs for tpi heads from 305.
Thanks! Have a nice wekend.

 

Try running the casting numbers at a website called mortec.com.

As far as the compatibility, your heads should work fine with your 305.

 

Yes they will be OK, they are the perfect thing you need. They should have a casting number that ends in 081.

Valves are 1.84" intake, 1.5" exhaust... same as what you ahve now. That's not what makes them different, it's the port design.

Port them before you pt them on.

 

I,ll do that Thanks!!