Slant 6 head interchange: 1975 head on 1969 Block?

Val69_170, sorry, didn't mean to hijack your thread. Dan, thanks for the info! I'm learning (trying to anyway). I guess the real question is if, other then no longer having to do adjustments, is there any real advantage to running hydralic lifters in a street/strip car? I'd think the solids would perform better. I won't butt in anymore!