I need help choosing heads for my engine.
I have a TPI 350. It has:
58mm throttle body
Ported plenum (from corvette plenum)
SLP runners
Ostrich for tuning the ECU
I will be using the LT4 hot cam and haven't decided weather to use 1.5 or 1.6
roller rockers.

I have a set of Pro Action heads which have 220cc intake port. These came off a 600hp drag car so I think they will be to big for what I'm building.
Would I be better off with a smaller set off heads?

 

220cc is total overkill for any TPI setup, no matter how much you port the base. Even 195cc would be borderline too big for your setup.

 

Thats what I was thinking. I might get some edelbrock performer rpm heads with the 180cc ports and use the other ones for another project.

 

180cc heads should be ideal for that setup. They'll flow plenty while still maintaining good port velocity in the lower rpm ranges where a TPI system really shines. 220cc heads would even be overkill on a hot 383 motor with a great flowing intake setup, let alone a TPI 350 motor!

 

As Air_Adam pointed out, 195's would be borderline for a 350. It can be done mind you, but the 180's or 190's would work better. I disagree with the statement regarding the 383 however. Port velocity is the most important thing for keeping the tq up, but with a 383's longer stroke would bring the torque back while allowing you to get the hp as well. Keep in mind that the
LS1 uses 200 cc heads. It makes great power but lacks the tq of a traditional tpi or lt1 motor. The reason the ls1 can use such large ports and still be streetable is because of parts match up. A better idea for choosing your heads would be to pay attention to the airflow they create between .150-.400 lift. This is where your motor will spend most of its time, regardless of duration or max lift. Some may disagree, but I'll stand by what I've said.

 

Thanks guys. You've confirmed what i was thinking. If i can't sell the heads I might use them to build a 383 stroker for my Torana and maybe supercharge it.

 

Sounds like a plan. Good luck with your engine idea.