I have the mods in my sig. and have been debating on a set of heads early next year. What would be the advantage of buying a new set of heads over just sending my stock ones out be ported, etc....? I have the Trex cam and don't really want to do any flycutting.

 

Most aftermarket heads start life with better port design. They also usually incorporate more material so serious porting won't compromise the structural integrity.

 

if you get rhs heads they are rolled over to 11* from 15 so you end up with much less chance of needing to clearance your pistons for the valves.

 

Yeah I didn't think about that. That makes sense. Thanks

 

That may be something to think about. Where can I find these?

 

I would look a TSP and see if they have stock on a set of ET Perfaomance heads. RHS heads are a ETP bare casting with RHS CNC port work. I had bought a set of RHS bare CNC heads and put a set of Ferrea valves into them instead of the REV valves that they come with. The heads did not flow close to what they are advertised to be on a bigger 4.125" bore fixture. The RHS heads are also MORE expensive than the ETP heads. Even with the RHS heads having lower flow number's we were still able to get almost 500 rwhp out of a stock bottom end LS1 engine that had 93,000 miles on it.