Join Date: Nov 1999
Location: ...and then I jizzed in my pants....
I can speak from experience that the 7.5 has slightly small axle tubes. We installed a Ghetto-Rigged PHB and used an axle mount that clamps around the tube on the driver side. The PHB originally came off of an 8.8 car and it would not fit our housing because it is a little smaller. The clamp part bottomed out and it was still super loose on the housing. I ended up taking some 3-inch exhaust tubing, splitting it down the center and weling it to the axle tubes, and then put the clamp on axle mount. It works fine now. The MM PHB uses a totally different style of axle mount so you should be fine, but yes, there are outside differences between the 8.8/7.5.