Hi this is my first post can anyone tell me the size difference from a Muncie with the bell housing compared to a Pontiac turbo 400.I am currently planning to install a drive shaft loop in my 71 lemans sport that now has a factory Muncie 4 speed and in the future a may run a turbo 400 and I have the interior and rugs out now and want to install the drive shaft loop and NHRA wants the loop a maximum of 6 inches from the front u joint and I don't want to have to drill my floor boards twice if I don't have too. Any help wouldd be appreciated.