I have a '71 Cuda with a B-body rear and DrDiff 1" relo kit.
I'm planning on running ProTrac N50-15's.
What seams to be the best back spacing to go with on a 10" rallye wheel. 5" or 5.5".

Thanks!

Bump for the west coast members! Surely gotta be somebody has run this by now

I have the 15x10 rear wheels on my 70 baca ruda, but unsure how much backspace my kit was. I'll get some measurements in a bit.

Thanks Miguel! Appreciate you helping me out! What size tires are you running?

no prob. 5.5 back spacing on b-body rearend, though the purches have been modified from stock.

current tire size was cooper cobra 295/50R15. Used to have BFG 305/50R15.

Say. you wouldn't happen to have pics of a e-body cuda fuel line right above the front spring hanger would you?

Thanks for the info! So the perches are narrower than the original B Body of 44"?
I'm sorry I wish I could get you that pic. My car is on the mainland and I only have a '69 RR here.

the purches were modified, but the back spacing should be pretty close to the same. Previous owner did the work, and most of it was not 'top notch' stuff. The spring purches look to be off by a few degrees, but he did have tons of clearance for those tires.

I have Dana 60 B-body rear out of 69 RR and DrDiff 1" relo kit on my Challenger. I used 5.25" BS on a 9.5" wide wheel so I would think 5.5" would be best.

Backspace needed depends on what year the rear housing is. 66-67 B bodies have a different width than 68-70, both of which is different from 71-74.

66-67 rear will need 5" backspace. 68-70 rears will need 5.5". 71-74 I've never bothered to check.

66-70 B body spring spacing is 44", which is a drop in, bolt up deal when you moved the E body springs in with a 1" inboard kit.

RTSE4ME and TC, thank you for the input! Much appreciated!
Just realized since I ran disc brakes out back the rotor hat is thicker and will be best with a 5.5" to make up for the thicker rotor as well.

Thanks again!