i need help w/duster engine

I know what claying is...we did it to our.Whaley terminator outlaw engine.
ok a couple of things......
i am not sure...what i read so far...
i cant put a roller cam in this because i have stock length valves..?
and i wont be able to run enough spring pressures.?
what if i dont go .600" lift...like chepstreet duster said..?
Am i just stuck with this..?
Again maybe i am missing something..but why cant i get the data in need
by measuring the valves with the head still on?
i can do a measurement at 25* before and after if i need to..some one mention'd that?
aarrrrGGG....?
Mel...
You can use stock valves ona roller cam.
You could get the data by using checking springs and leaving the heads on. Check piston to valve every 2° from about 100 crank ° before TDC on the exh stroke to about 100° past TDC on the intake stroke. Somewhere in there is the closest point. Or just pull the head and turn it over once with clay... In any case, roller cams are not simply drop in in most cases. Your impatience and youth is really showing right now. That's a good way to hurt parts.