The factory big block A-Body's had a 22" 3-core radiator with the drivers side lower hose and worked just fine. No reason to use a 26" radiator, cutting the core support will just make it ugly when you can just use the right parts to begin with.

The funny thing about science is that if you change one miniscule parameter you change the entire outcome to the way you want it.

JB Rhinehart, Realist

A-Body's RULE!