How are you planning on doing it? Aftermarket tubs or sectioning the stock tubs?
When I did mine it was using the stock tubs with patches where needed. It would have taken half the time and and I would have gained 3 more inches of room had I used an aftermarket tub. I could gain this room if I'd cut the outer sides of the tubs and build them to come flush with the quarter panels, its not needed with a 315/60/15 on a 10" wheel but would be if a 12" wheel is used. I still have pics of the process if you need any. Its best to do this before final paint if you plan to secure the wheel wells by more then seam sealer in this area, lol.
I'm assuming with that wheel selection your planning on narrowing the rear and relocating the leaf springs? The best advice I can give for this is to set the car/tires at the desired ride height on jack stands without the rear and position the mounted tires where they will clear everything in the wheel well. FWIW my housings have been 49 1/8" outer end to end not counting the axles and brake hats. At ride height it is a tight fit, but I've lowered the car 4" from stock, about to be 1-2" lower now that I have more clearance since the POS dana is in the dumpster.
Keep us updated.
