Which bates the question as to which heads are we talking about? Pro Topline was an Australian head caster that went out of business a decade or more ago. The molds drawings and rights to the complete Pro Topline line of heads including the foundry where purchased recently by the former Racing Head Service corporation (a company that went bankrupt about three decades ago but before it died it had spun off their line of cams and springs as separate company which was doing business as Comp Cams.
Comp Cams has resurrected the old RHS logo and is using old Pro Toplline heads to get back into the head casting business again as nothing succeeds in today's business world like a monopoly. They RHS also doing business as Comp Cams claims to be developing all new head designs using their labs and CNC equipment to create competitive heads at a competitive price.
But the question I ask is are you referring to a GM casting Chevrolet small block head that has a saw tooth pattern on one end, or a set of somebody else's heads? The Chevy heads are easily identified by their unique casting mark:
here is the side view of the head:
Note the extra bolt hole on one end.
The Vortec heads are valve lift limited to 0.480 inches stock and at best can support 0.520 inches of lift at the valve when fully machined. Here is a machined head showing the finished work on the left and stock machining on the right. You have to cut a larger spring pocket and cut down the valve stem guide to use PC oil seals to get 0.520 inches of lift.