They heads you have now show nearly identical flow performance up to 0.500 lift. Why bother?

http://static.trickflow.com/global/i...%2C030bore.pdf

 

Those flow numbers are NOT at all impressive to me. I'd look for flow in the range of 240 cfm at .400" and in the area or 260 cfm at .600 valve lift, with a port volume of less than 200 ccs.

If I was deciding between two sets of heads, (one with 195 cc and the other set with 180 cc intake ports), but both flowing similarly to each other at those two valve lifts (.400"/.600"), I'd go with the smaller port. I'm an advocate of smaller ports to keep the velocity up.

Also, from what I've read, LT4 heads are 195s. So 195s aren't over the top, but to me, those cc ports are best suited to 383s and up.

Also, the 218@.050 cam previously referenced in a link, is in the same duration family as the GM HotCam. So it's well suited for a 350ish CID street performance engine.

Jake

West Point ROCKS! Nation's TOP COLLEGE per Forbes Magazine!

 

I agree with JAKE and TequilaBoy. The head you're eyeing has little-to-no advantage than the one you're running. It's not very good -- especially for a ported, blended specimen.

If you can swing the 383 and don't have any objections to it, who here would say NOT to pick it!!! But, when a budget gets in the way, there are choices to be made.

I don't see whether you have an auto or a stick. For me, that could make a difference how to proceed next. It would however be hard for me not to suggest a 383 in your situation, but that is debatable. The TFS heads are slighty better than the average aftermarket head but there's lots of room for improvement. As Jake's pointed out flow is more important the intake runner CC size -- if you've not figured that out yet. When two heads flow the same, have more port volume doesn't help you. And, it can hurt.

A better flowing head could be used by that FIRST because it flows so well compared to any other TPI. OTOH, a 383 needs more air too. The tricky part is to determine which of the two options best fits your needs/budget. But, I think it's safe to say a 383 would perform way better at lower-to-mid rpms. But better heads would pull harder from 4k rpms until you shift. If it's an auto w/o plans for a shift-kit, the 383 might just be more fun. Otherwise, if you can get decent money for the TFS heads and wanna look at a really nice head (like an AFR or ported TFS/Dart) then you'd also get an improvement and be in a better position to throw a 383 underneath it.

It's kinda that torque vs HP argument.

 

Yah I deffinitly see what you are talking about, and I understand the flow vs runner cc thing. I think for now I will stay with what I have. I know the car pulls great. I think the most I am gonna do is clean up the ports on the FIRST and maybe on the heads to gasket size, and put the rest of my money into paint, rear wheel bearing, weatherstrips and wheels/tires. Thanks for all of the kind advise. I dont want to start a hp vs torque argument.

Peace.

 

Smart man.