.620 mechanical Purple Shaft?

I have a lightly reground Mini-Express mushroom setup in my 451 and have fun with it on the street (4-speed and 3.91 gears)
(Original cam specs: .654 gross lift, .024/.028 lash, [email protected]). After restoring the lobe taper: .652 gross lift, .018 lash, [email protected]. Idles at 1100 rpm or so, 8" vac. It really starts to come on above 3000 rpm and so far I haven't had the nerve to find the high end of the power band :D

But that GK mushroom (or even the .620 FT) is an awful lot of cam for a 383. You'll have to wind the piss out of it to take full advantage, and hopefully your 915 heads are ported some too.