Originally Posted by Juggernaut

TEA has proved to be one of the best sponsors you can go with time and time again. Between their products, price & customer service they are hard to beat. I would say 400-425hp would be a pretty easy chore for a 408 with their heads and any kind of aftermarket cam.

http://www.totalengineairflow.com/pr.../gmhead/gmls1/

Ryan

Originally Posted by BigTex

My thoughts:

TEA, DART, AFR, even Patriot - these are not budget heads that you would want to modify yourself. TEA and Patriot will be pre-ported stock heads; DART and AFRs will be a completely new head design.

I suggest you start with stock 6L heads, add some larger valves, do a valve job, unshroud the valves, and give them a mild hand porting to remove the stock casting material. This way you start with an inexpensive good design and make them better while learning in class.

Flat top pistons and achieving 10:1 compression on a 408 will require either a large chamber or a valve relief / dish in the piston. You'll learn the math in school I'm sure.

10:1 compression is going to be a little low I think. I suggest you shoot for something between 10.5 to 11:1, which will run just fine on good pump gas and have no problems of detonation or pinging. The LS6/6L head design really works well with high compression and fighting off detonation.

Budget wise, I suggest you find a complete motor to start with. Look for a GM service pull motor that has some minor issues, since your rebuild will correct any problems. Cost wise, a used complete 6L will be the best deal compared to buying a block, heads, and the misc parts to finish it. Those little parts start adding up if you have to buy them seperately (covers, pan, reuseable bolts, lifter cups, rockers, ...).