Al,
My Holley 4V uses the outer holes, but it depends on the carb used, I'm going to use a square bore 4V and the butter fly is front to back, my son's quadrojet 4V is mounted with the primaries closest to the head.
After looking at everthing I decided that there may be little difference mounting it one way or the other for fuel distrubition! But with my 1968 Mustang if I mount it any other way the carb won't clear the shock tower..
I'll let everyone know if theres any problems mounting it this way as we will have one mounted both ways on Aussie 2V head's to compare results.