Probably plenty of cam for an automatic in a pickup--get the right stall converter it should work. Might want to check over that 'rebuilt' short block....some rebuilders don't use the best components in them, for sure it's just a set of cast pistons. You'll have to check the bore to see how crazy the shop got on the honing and how big the bore is now, piston to wall clearance is going to be different with a hypereautectic or a forged piston so you'd want to make sure the cylinders aren't too big already.

Don't know much about the Vortec heads, I know of a few local guys running them that seem to make decent power. What gears do you have in the rear end of the pickup? Doesn't do much good to have an engine built with some decent power then having it going to some lazy highway geared rearend so you might want to check that, too.