My rear is 54 3/4" Fab9

Is that a WMS to WMS measurement?

I have 18x12's with 5.625 back space. 54.75" axle flange to axle flange
68 camaro

714-345-3865 text for pics

Not sure. Just reading off the receipt from when it was ordered. I believe it is the total width.

The housing flange to flange measurement is irrelevant to the discussion of fitting wheels since different axles can change the actual Wheel Mount Surface( WMS) to WMS dimension. When fitting wheels the only measurement that means anything is the width from one WMS to the other WMS. This is where the wheels actually seat on the rear end assembly.

That 54.75" is from housing flange to housing flange not axle flange. The WMS to WMS of that rear end is in the neighborhood of 57" otherwise those wheels will not fit that car. My 18x12 5.6bs wheels are running on my 57" WMS to WMS rear end.

I'm just finishing up a 67 with 17x12" rear wheels, 6" BS. I had the 12 bolt narrowed to 55" WMS to WMS. Running a 315/35/17. The rear in my 69 is 56" WMS to WMS running 18x12, 6" BS and 335/30/18. Both cars have rolled fender lips. Each car is a bit different, but I have nearly equal space between the tire/fender lip, and tire/inner wheel house. Hope this doesnt muddy the water, just thought it may help for comparison. Scott

just to make sure I understand WMS is the measurement from outer surface of the brake rotor (wheel mounting surface)??? correct?

The measurements I listed are without the rotors, but yes, the outer axle flange that the wheel studs go through. I take the rotor thickness into account, but dont measure with them mounted.

Steve couple questions, what tire size are you running in the back and did you need to modify your front inner fender wheel wells? Understand you rolled the outer fender lip but i was more concerned with the inside clearance.

Thx
Tony