Fella's, tire & rim size question


New Member
Jan 14, 2021
I've read thru the "are these tires & wheels gonna fit" Q&A and I think I'm more confused now. I have an 87 gn, Moser Ford 9 rear" (stock application), no frame notch, no fender roll or fender notch, no wheel well molding, HR Parts rear suspension, Synergey body bushings, Baer brakes (SS4) and Ridetech air ride (Gen 3). I want to use a Weld 15x8 4.75" bs beadlock wheel.
Weld strongly recommended the 4.75 bs. I asked them about tire size and fitment, but they won't comment. Told me I had to figure that out for myself. They just said to stay within the recommendations of the wheel specs.
I've done some measuring (if I did it right) and it seems like the car is pretty evenly centered. I've measured off the frame and I've measured off the rotor with a tape measure and a 4' level placed on the the floor to the outside side center of the wheel well. If someone has a better or more accurate way then please let me know. I imagine a plumb bob would work too.
There's only a few tire sizes that I can probably use. I'd like to know what you all think will work best. I'm only interested in rear wheels. I think the three best tire sizes would be: 255/60/15, 275/50/15, 275/60/15 using the MT ET Street R.
I've asked Ridetech for some help, but they haven't been very helpful.

Thanks all
Ive had those dimensions 15x8 4.75 on a few G bodys , they all work although no experience with air ride .. 275/60 look/hook the best