What size tires(35's) will fit a 20x10 wheel? preferrably larger

 

Any 35x12.50 to 35x14.50 will fit. Some members have even used 15.50 inch wide tires on 10 inch wheels with no problems.

 

A 12.50 is roughly a 325?

 

is the backspacing half the wheel size?

 

325 is about 12.8" wide, 315 is about 12.4". Backspacing is not half the wheel size. Here's a link explaining it: https://www.rsracing.com/tech-wheel.html

 

Thanks for that conversion chart. I figured it out. The rim I was fixing to buy was 20x10 with a 44mm offset like my stock rim. Too much backspace. even with a wheel spacer most lift kits Ive looked at have a max of 5'' backspace.