The LS based engines are light years ahead of the traditional SB and BB
chevies. I have ported several sets of heads for these engines, it's easy
to get these to make big power.
I decided to make the switch myself, I picked up two engines relatively
cheap, a 6.0L iron truck engine a LS2 aluminum corvette engine. I bought
a new set of these L92/LS3 heads from GM for $350. I haven't decided
on compression and camshaft yet, I will be talking to Mr. John at bullet
for the cam. As for ignition I will be running the stock coils with a MSD
"The L76/L92/LS3 cylinder heads are the most advanced small block heads to
date. They use 2.165" (55 mm) intake valves, and 1.59" (40.4 mm) exhaust
valves. For use with 4" and larger bores, they allow for over 600 hp naturally
aspirated. Improved manufacturing efficiency makes these heads cheaper
than the outgoing LS6 heads, and severely undercuts aftermarket heads. The
large valves, however, limit maximum rpm - 6000 in the L76 (with AFM), and
6600 in the LS3 (with hollow stem valves)."