looking for wheel sizes and backspacing for wheels to fit my car and clear in the rear? looking at weld wheel rts 76 and alot of widths and backspacing options? not sure what will fit? i have a dana, not sure if it is same width, as a stock rear end or not? don't have an old one to measure? thanks moparts

A lot of it deends on th etire too.

If you are going to use a stock height tire that isn't too wide stock offsets work fine. If you are going to go with a max size that can be stuffed in there tire you will need wider rims and you will need to measure your ride to see what will fit because body tolerances are sloppy.

have a good way to measure? never had to do this before. looking to get a nine and a half wide on the fear and a seven inch on the front? just seeing if anybody has that combo on there car. weld is a order for your car only and don't take them back if they don't fit. thanks moparts

Take a 2'x 3' piece of cardboard and tape it to the floor under the wheel well opening. Then use a plumb bob and mark all the edges of the opening including the hub on the cardboard.

Do both sides as they can vary.

This will give you a very accurate footprint that can be easily measured. And when I order wheels, I always order them about 1/8 inch extra to the inside. That way, if they need any 'adjustment' when they arrive, they can be shimmed outward a lot easier than they can be brought farther inward.

You probably want to use a 17x8 rim and a 235/55-17 tire. That combo should fit most B body cars and it will look good. Mopar wheels typically had 1/2 inch of offset. So on a 8 inch rim you would have 5 inches of backspacing.

There's a few ways to figure this out:

1.Dave's plumb bob method is good.
2.Mount a wheel (no tire) up, support car by suspension, break out the measuring tape.
3.Wait for guys here to chime in with what they've done, which may or may not work for you.
4. Get specs for the wheels & tires you like; for tires, section width, OD and rim widths recommended and used for measuring.

'68-'70 B-body rears typically use a 4.25-4.5" BS up to 8.5" wide, after that 5.0-5.5" gets a 10" rim in there. Usually 29" is about max OD, max section width that fits is around 12.5-13.0"...BUT as stated cars vary, including side-to-side.

is that back spacing with a 15 or 17 inch wheel?

is that back spacing with a 15 or 17 inch wheel?

14 or 15; don't know if it would be much different on a 17 without measuring. I know the 17s on my Mustang have very little sidewall bulge compared to the 15s on my Mopars, but the 17s also have an aspect ratio of 35 & 40.

You really need to measure accurately and add for tire bulge when trying to determine backspace...
On my 70 I think I've heard others say the wheel well opening is larger than a 69.
I have 275/60/17's on the back of mine and it is stuffed...I also had to slide the rear end back with a spacer in front of the spring perch for the tires to clear the front bottom edge of the 1/4 panel. These tires I have measure 30" tall and have a 11 1/2" section width....
They are on 17 x 9 1/2 in rims with 5 1/2" of backspacing.
After the first year I ended up using a 1/4" wheel spacer behind them. They only ever rubbed on angled odd entrances and exits...
Using a 5" backspace would be conservative towards the spring side...and as mentioned above tire bulge and the overall length of your rear will change everything.

what size did you use on the front? nice car by the way!

Tires are 215/70/15's
Wheels are 15x7...I think they're a 3" or so backspacing...