Just got home guys...lots of super responses! I screwed up and should have mentioned the gentleman actually has a 68 340 GTS, but the original 340 is gone. He has a 383 with the correct 383 K frame, motor mounts, exhaust manifolds and rebuilt big block rad! Also has a '70 340 with hi flow manifolds and correct rebuilt 340 rad.
A tough decision for sure. I think the 383 with the correct pieces may edge out the 340?