Yes the stealth heads are a possibility, but my 906's already have good springs, 2.14 and 1.81 valves (back cut), chambers unshrouded and decent bowl ported... I know that they won't like the pump gas as much though?

ScatpackTom, from the look of your sig, you already have my recipe!!! mine is a 4 speed as well, 4.10 Dana.
You are running exactly what i want it to run.
Care to share?

Cheers,

Arnie