I'm putting an MII front with 2" drop spindles on a '55 F100 and am looking for some advice on wheel back spacing. The tire/wheel size I'm considering is an 8" x 15" with either 235-60-15's or 235-70-15's if I need to get the front up a little. Measuring things out, it looks like a 4" backspacing will work but I would like to hear from anyone that has already done this. I also want to make sure there's no fender rubbing at full lock. All help is appreciated.

 

I have a Heidts Mustang II IFS on my 56 I am using 15x7 Cragar rims on the front and had the same question you have. I sent Heidts a Email and they recommend for backspacing for this setup 3 3/4" Backspace.This is for the front tires 225-75-r15

 

I know it's in that general area. The only one I've been able to measure so far is a Volare set up and that used a 4" BS. I'm going to use the TCI kit but that's like comparing apples and watermelons.

 

A 235 section width tire doesn't need an 8" rim. In fact, it's probably at the extreme of acceptable rim width for that tire. A 6" or 7" is plenty. A 60 series tire in that size is pretty short and won't fill the wheel opening very well at all, imho, fwiw.

 

I appreciate your comments and I agree on the 60 series height, but the tire charts say 6-9" for rim width and we have 235-60-15's on the wife's 8" wide Rallye rims on her Pontiac and they fit very nicely. Would have gone 255's but there was a fender clearance problem on the Ventura. My concern right now isn't so much, the specific tire, but rather the best backspacing on a 8" rim for the front.

 

for what it is worth, I'm going with 15 X 5.5" wheels on front with 4" -4.5" back space. Haven't got wheel back from shop , will decide on tire size after I prime and paint wheels.



This is pic of 15 X 7 Ford Crown Vic wheels with 4.5" backspace. My dimension probably don't apply to your '55.

Tom

 

I am running 16x8 with 3-3/4"B.S. on my MII with 2"dropped spindles. No clearance problems. I also have 11" rotors.

https://www.ford-trucks.com/user_gal...140138.520.390

 

I have the Mustang II front end with 15x7 rims. No issues with clearance or anything, cant remember what tires I have on the front.

Although I really liked the look/rake it seemed to drag a bit on the bumps with the dropped spindles, so I got the stock spindles and put them on there. No rubbing on the crossmember or fenders then, but also I have a 460 in there, so there is a lot of weight. Good luck.

 

Yeah, the drop spindles are a concern, hope it doesn't end up too low. I know I can always go to standard, just hate wasting the $'s. I have a fuel injected motor of a brand that shall go nameless and I'm sure it's a lot lighter.