1936 Chevy sedan wheel spacing
 

I just purchased a 36 chevy standard 2 door sedan with a mustang 2 suspension already installed, it has 14 inch wheels with a very positive offset and they extend to the outer edge of the fender. i would like to go with a 15 or 16 inch rim with a wider tire. anyone done this or have sugestions on backspacing?

Just remove the offending 14 inch rims
Measure the back spacing and then get a 15 inch rim with more back spacing.

https://www.rsracing.com/images/tech-wheelfit1.gif

Go here for a better understanding of rim offsets and fitting wheels to a vehicle.

https://www.rsracing.com/tech-wheel.html