Backspacing?

[renegade8720]

Hi, I need advice from the Lords of knowledge. I am getting ready to order my wheels for my 1950 3100 truck.
I will be using 15" wheels. I am building a pro tour, and will be using 15 x 14 with 4" to 5" backspacing in the rear bolted to a narrowed 9" rearend.
I will be installing a mustang II front end with stock height spindles. I want to use 15 x 7 wheels and want to know what backspacing will work with this front end set up. I don't want any fit or rub issues when turning.
Please give some advise on what backspacing will work.

Thanks for your help,

Renegade

[Bob@ProAuto]

If you are using the original 9" Mustang rotors and a 15" wheel, 3 7/8" is the most backspacing you can run. If you are using the bigger rotors, then you will need to check with the manufacturer and see if the hub width is wider and by how much.

[mr48chev]

If you don't go over an 11 inch rotor I think you are pretty safe with the 15x7 wheels with just about any backspacing you might run but you still have to factor in how the wheel and tire combo will fit the wheel well/inner fender.

Will the tire be too close to the lip of the fender or set so far back that it looks lost in the wheel well.

Is the tire the right height for the stance of the car. This is the biggest mistake I see guys putting AD trucks together make. A lot of them want way more tire on the front than the ride height and stance allow for.

From what I read into your lead post I think you have that handled and are now looking for the offset that will clear the suspension and still look right.

Depending on the wheel's you want to run you might talk to the manufacture's tech reps and see what they say.

[Bob@ProAuto]

Actually, not all of the 11" rotors measure the same.
Mustang II stock hub width is 57". Pinto/Bobcat is 56.5"
When we use an 11" Ford rotor, it increases the hub width by 1" total. The Chevy rotors only increase it by .625"
You can see that depending upon the rotors, you can actually increase the backspace.

[Houston54]

On the front I would think that 4" would work well for you. If you are running big rotors on the front or the rear then the 15" rims will NOT work unless you space them outward.

You do not mention if the rear is tubbed. The 4-5 inch spacing you specify for the back is a large window. I am running 15x7 GM rallys and that have a 4.25 back spacing and they rubbed the bed sides until I put a space in.

There are several wheel manufacturer sites that have good information on how to determine what BS you need. I would suggest you find one and perform the measurements they identify to see what will fit your set up.

[Arkansas50's]

Here is some info that may help.https://www.rsracing.com/tech-wheel.html

Most custom wheel makers will have their own form that factors in wheel wells, frame, brakes, ect. Call your favorite.

[renegade8720]

Thanks for all the advise!

Renegade