What is the correct back spacing needed on a 15x10 Cragar on a 69 Road Runner.

Last I heard, 5.5" works on a 15x10 for that application.
That assumes stock & original everything.
I'd sure measure the heck out of the car and existing wheel/tire fit - both sides.

You really do need to measure as any tire that is an appropriate size for a 10 wheel is going to be very close even if it is perfectly centered between the spring and the wheel opening lip. What size tire? Do you know what the section width is when mounted on a 10" wheel? Also you should measure both sides of the car as it is not unusual for the rear end to be off-center some. You may need to correct that to maximize tire clearance.

most of the wheels are only avail in 3.5 or less backspace anymore... i was trying to use them on my 70 challenger and had to go with the 15x8 instead... which was 4.25 BS iirc... keystone mag

Did they ever come with a 7.25" backspace (for A-bodies)?

5-1/2 BS is what you need.

BS !!

Agree but the Crager catalog only shows 3 3/4 and 4 1/4 BS in 10".
Crager used to have a custom shop but it closed.
What I used to do many years ago is buy the 15x7 reversed which.comes with 2 1/4 BS.
I would take them to a local circle track shop and have 3" added to the back side
resulting in 15x10 with 5 1/4 BS. Close enough.

What Cragar sells is not my problem. The question was "what BS for a 10" wheel on a '69 RR" and the answer is 5-1/2"

On my 68 Charger, if I had a 5.5 BS it would hit on the inner wheel tub when turning, I have 15x10 4 7/8 BS 325/50/15 & it just barley rubs the inner on a sharp incline turning, stock width S60, on a big bump the tire will just graze the outer tub hump, I should have removed that B body hump, when it does hit there is NO mark on the tire,

Perhaps, but Cragar was a condition of the original question that you chose to ignore:



Now there are numerous Cragar offerings and perhaps they have a style of wheel with the required backspace. However, If we are discussing the venerable SS , which is popular on this era of car, this combination of requirements cannot be met.

Don't be an idiot. Regardless of the wheel manufacturer and whether or not they make it, the required backspace doesn't change. It's 5-1/2"

On my 70 Charger, I'm using Magnum 500 15x10 with a 5" backspace. 295/50/15 Dana 60. Fits perfect.

Original post

With a stock width rearend a 5 to 5 1/2" BS is needed but not available from Cragar. My previous post explained the only way to get there with a Cragar. To be clear on the 69 B body that I did this on it fit better than the 5 1/2 BS aluminum wheels that were put on at a later date which needed 1/4" spacers to get the tire (295/65-15 M/T) further from the spring. A smaller tire might not need a spacer with a 5 1/2 BS.

I have done this same mod with chrome reverse wheels and Keystones.
Way back in the mid 70's I used the same method to widen 8" Cragars for a 70 B body that was mini tubbed and springs moved into the frame rails.