My 455 is an early year and has the "430" alternator.
I'm not interested in front, rear, anything other than stock location options.
I would consider the "hot rod mini alternators" vs an actual 430 one as they are similar.
I have a fair amount of room:
Yes the frame ground is good. I have even grounded the voltage regulator straight to the battery and didnt change the situation. I will check the ground from the battery to the engine at the block too, but it cranks over fine.