from 10" to 12" backspacing change?

4doorbu

Pro Stocker
May 21, 2003
1,877
0
0
south jersey
I'm going to be switching from a 10" rim with 4.5" bs with a 325/50 radial to a 12" rim with 295/65 radial. do i just need to add one inch or take away or what to get the correct backspacing. $400 a piece :shock: rims are too expensive for me to guess!
 

bukweet

Top Fueler
Mar 22, 2005
2,803
0
0
Mississippi Gulf Coast
For frame clearance, my thought is backspacing would remain the same regardless of rim width. The distance between the mounting surface on the drum and the frame rail is the same, no matter what rim/tire combo you run. The amount of bulge on the sidewall might effect it but you appear to be going to a taller, not wider tire.
The outside fender clearance is where you might have a problem
I might be wrong, I have been before.
bukweet
 

Supe

MalibuRacing Junkie
May 21, 2003
15,116
0
36
Charlotte, NC
On a stock width rear and a 12" wheel, you'd run out of frame to notch with 5+" b.s once you factor in the sidewalls of that 295.

Double check with Paul F. He's got the 295 on there, and you can figure out the fender to tire clearance. He's running a 12 bolt with 10" rim, but you can do a little math and come up with it. He has the tire as tight as physically possible to that fender lip. You can't even fit your finger in there with the inner lip cut, yet he has never cut into the tire.
 

MalibuRacing.com Gear

Stickers & Shirts!!

Latest posts