Rear wheel and tire size questions

[Blown71]

Hello all I'm new here and wanted to stop in and say hello.
I'm curious about how wide of a tire will fit under the back of my fleet side 71 before I have to narrow the frame. I want to go as wide as possible and I don't mind trimming the wheel tubs in the bed I just don't want to get into frame surgery at this point. My big block is supercharged and traction is hard to find. If anyone is willing to share their wheel and tire size I would appreciate it.

[un4gvn!]

I didn't touch my frame or narrow the rear end. I also kept the original brake drums. I took two original 15x8 ralley wheels and had them widened to 12 inch's with 7 inch back spacing. I split my wheel tubs in half and added 7 inch's to them which put them right over the frame. I also cut my bed floor back to the frame. I wanted to widened my wheels to 14 inch's with 8 inch back spacing but someone talked me into going with 12 inch's. I mounted Mickey Thompson Sportsman 29x15x15 tires on the wheels and bolted them on the truck. I had enough clearance for my original idea widening the wheels to 14 inch's and use a taller tire. But mind you, when I had the tires mounted on the wheels, they weighed a ton. I haven't had the other wheels widen yet for fear they would be way to heavy. Thank God for six lug wheels. They do look cool.

[Tiger Joe]

I have a 67, so our rear axles are different widths.

Here is my tire and wheel combo:
Rears 275/60-15 on 15x10 with 4.25 bs
Fronts 245/60-15 on 15x7 with 4 bs

Based on my measurements I could have gone as wide as 12" in the rear with the 4.25 bs. that would have been extremely close however. current setup has not one rubbed once.

[Blown71]

Thank you for your replies I appreciate it.

[geezer#99]

Did you know they make a handy little tool to precisely measure with.
https://www.summitracing.com/int/par...1201/overview/