69 A body rear wheel offset

My first post, hello to all.
I have a 69 Barracuda and am making some needed changes to correct what the previous owner did to the car. Before I buy wheels and tires I am hoping to get some advice on what works. I am adding the 1/2" inboard spring relocation kit from Dr.Diff and am looking to find out who has proven the back spacing for the rear wheels as well as tire width that fits inside the stock rear tubs. If you have already been thru this and know what works please let me know. Thank you!!

Do you know which rear end, type (Dana 60, 8 3/4, 7 1/4, 8 1/4, 9 1/4 or?) and original body style it came out of? If not, do you know the width it is from the axle bearing flanges to the other side with no brake backing plates? That will help us help you

1969 Barracuda

Factory 8 3/4 rear (not sure what year the rear is though as there is a small difference in width between years)

Rear 15x8 with 4 1/2" backspacing use a 275/60R15 Tire

I did have to add a 1/4" spacer on 1 side and a 1/16" spacer on the other to get 1/2" space between the tire and leaf spring. Leaf springs are mounted in factory location.

Thank you for the replies. It is the factory 8 3/4" that it came with. 4 1/2" is kind of where I was thinking and am very thankful for the measurement. It seems like I should not have any clearance problem with the extra 1/2" inward spring location that I am adding verses yours with the stock spring location. The 275/60R15 on 15X8 wheel is exactly the size I wanted to go with too!! Just over 10" wide should work great!! Thanks again, very appreciated. Now its time to start making it right!!

IIRC THE 4 7/8 B/S ALLOWED THE BIGGEST TIRE WITH DECENT CLEARANCE,,