Yep, what he said. You'd have to pull the heads and have a machine shop pull the studs, tap the holes for screw in studs, and get pushrod guideplates. You may end up buying different pushrods as well, to get the tip to contact the valve stem corectly. Basically, if you aren't rebuilding the heads, forget it.
The rockers SHOULDN'T have been damaged by the motor blowing up, you just need to inspect each rocker for any type of damage. FWIW, you can get cheap full roller rockers for about $130 brand new.
Dorian
My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>