[radz28]

Trick Flow have been proven to be not only popular, but flow really well on LSX engines. I can't speak from experience, just from research and what I've found on the internet, but I don't think you can go wrong with Trick Flows.

I know that ETP has great heads too, if you're in the market for top dollar, top performing heads. They have everything from 11* 3.9" bore heads to canted valve LSX heads, like big blocks have had. They're crazy expensive, but know of a couple people who run them, and they have some bad@$$ cars.

I've read a lot of articles about Livernois (?sp?) ported 243s and 317 heads and those things flow like mad for OEM cast heads. They flow nearly as much as Trick Flows (205s I think) and are like $1K less.

I've read some quality control concerns with Patriots a few months ago. I don't know how that's panned out though.

GMPP and World are working on their own 6-bolt style heads for +4.10" bores for their respective LSX-style blocks. I know that Z06 427 heads are CNC'd and flow great and that there are great things coming from L92/LS3 raw and factory CNC'd heads.

Edelbrock has a redesigned LS1 head from what I understand but doesn't quite match AFRs that I've read so far.

SLP use AFRs and GM heads and custom CNC them to my understanding. I'm not sure you'll find too much a difference above or below anyone else to has CNC programs for these heads.

Just keep in mind if you have a 3.90" LS1/LS6-style block, you'll be limited to smaller valves. The L92/LS3 heads are substiantially better but require at least a 4.00" bore. You can't bore a 3.90" bore block out to 4.00" without resleeving. I'd recommend, if you don't know or haven't been there before, to go to LS1Tech. There's a wealth of information there. If you can't find the answer there, there's probably something wrong.