Wheel/Tire fitment on 65 Fastback

I have 245/60/15 BFGs on 15x7 rims on the 66 Fastback. Also, I occassionally run 235/60/15 BFG Drag Radials on 15x8 rims. There are no alterations to the body, but the rear springs are 5 leaf "standard eye" and the shocks are KYBs.
 
Thanks for the chart 66P51GT. I have seen that chart before, and i just don't know where my car would lie on the chart. I have heard that the tire will fit the wheel, and the only thing needed for clearance is enough backspacing. I do no wish to roll the rear fenders either. What backspacing options are there on a 15 X 7 inch styled steel wheel? Thanks again.

-Taylor
 
Hey Bifs66, would the 235 fit on the 15 X 7 even though you have it mounted on the 8 inch? I also have KYB shocks in the rear, but i do not know which leafs we have in the rear. All I know is that the leafs that are on the car combined with the block lowers it about one inch from right around stock ride height. The end result is about a finger length clearance between the fender and the top of our tires (presently 205/60/14 on 14 x 6). Thanks for the help guys!

-Taylor
 
TTBullitt said:
Thanks for the chart 66P51GT. I have seen that chart before, and i just don't know where my car would lie on the chart. I have heard that the tire will fit the wheel, and the only thing needed for clearance is enough backspacing. I do no wish to roll the rear fenders either. What backspacing options are there on a 15 X 7 inch styled steel wheel? Thanks again.

-Taylor

Don't know where your car would be on the chart!!!!!!
I try to make things easy to read and understand, maybe I can help, what part of the chart are you having trouble understanding? Do you know what rear suspension you have on your car? What brakes are you running? Those are the 2 things you need to know to get a definite answer from the chart.

FWIW 235 60 15 on a 15x7 is generally a tight fit (with regard to rolling fenders).....most people prefer to move up to the 8 inch rim where a better off the shelf back spacing is available.
 
Hey dodgestang, we have the stock drums in the rear with the stock leafs with the one inch spacer. I don't know what "eye" the spring is though. The car sits very low though with only a finger width clearance between the fender and the top of the tire. I would like to stay with a style steel wheel because the car is still a show car, so that is why i am trying to see what my options are with 15 x 7's. A last resort would be to just keep the 14 x 6's all the way around and purchase some other wheels (maybe welds, etc.) for the traction I need. What do you guys think is our best option? Thanks again

-Taylor
 
TTBullitt said:
Hey dodgestang, we have the stock drums in the rear with the stock leafs with the one inch spacer. I don't know what "eye" the spring is though. The car sits very low though with only a finger width clearance between the fender and the top of the tire. I would like to stay with a style steel wheel because the car is still a show car, so that is why i am trying to see what my options are with 15 x 7's. A last resort would be to just keep the 14 x 6's all the way around and purchase some other wheels (maybe welds, etc.) for the traction I need. What do you guys think is our best option? Thanks again

-Taylor

15x7 with 3.75 BS with 235 60 15 you will be tight..a 225 will fit for sure. What you are running is stock springs (with a stock eye) and a lower block...that will roughly equate to a 4 leaf mid eye in rear posistion. I see an couple entries with people saying they did not need to roll the rear fender with stock 4 leafs...but that isn't with it lowered..... What tires are on the car now?...as a general rule if you stay between 25-26 total outer diamter on the tire you will be ok
 
Hey dodgestang, right now I am running a 215/60/14 BFG Radial T/A on the 14 x 6's all the way around. It seems there is plenty of room in the wheel well for more tire too. I know it is tight back there, but I just want to go as much tire as i can for maximum grip. After tuning, we will have around 300 rwhp and prob 310 ft tq with an auburn limited slip with 3.55 rear end gears.
 
TTBullitt said:
Hey dodgestang, right now I am running a 215/60/14 BFG Radial T/A on the 14 x 6's all the way around. It seems there is plenty of room in the wheel well for more tire too. I know it is tight back there, but I just want to go as much tire as i can for maximum grip. After tuning, we will have around 300 rwhp and prob 310 ft tq with an auburn limited slip with 3.55 rear end gears.

Have you considered possible moving up to a 16 or 17 ;)
I know how you can put a 255 on with a little rolling :)

I would look into getting a 15x8 especially since you want as wide as possible. a 15x8 with 4.5 bs and a 235 60 15 will fit in. By putting on in a wider rim you lesson the crowning effect and tighten up the sidewalls a bit.
 
TTBullitt said:
Hey Bifs66, would the 235 fit on the 15 X 7 even though you have it mounted on the 8 inch? I also have KYB shocks in the rear, but i do not know which leafs we have in the rear. All I know is that the leafs that are on the car combined with the block lowers it about one inch from right around stock ride height. The end result is about a finger length clearance between the fender and the top of our tires (presently 205/60/14 on 14 x 6). Thanks for the help guys!

-Taylor

Yes, the Summit catalog lists 235/60/15 BFG T/A tires as fitting on 6.5" to 8.5" rims. One issue with fitment is that the tires may clear everything with the car sitting still; but when you get moving, the axle start moving around and rubbing can occur. This is particualrly true with soft or weak springs. That's why I went with 5 leafs....to reduce rear axle movement in street driving situations. I didn't want to fear every bump or dip in the road which is why I chose 5 leafs and standard eye.
 
TTBullitt said:
So what are the largest wheel/tire combo that the 65/66 guys are running in the rear? Also, what does it take to roll the rear fenders? Thanks always.

-Taylor

I run a 255 40 17 with rear disc brakes on a 17x8 wheel
A friend out in CA runs a 265 40 17 with stock drums on a 17x8 wheel

We both have 4.75 bs, the difference is the spacing from the brakes, he had to run a spacer to keep the tire of the leaf spring and we both have rolled fenders.

I roll my fenders with a baseball bat between the tire and sheetmetal
 
Hey Dodgestang, thanks so much for your help. So it looks like an 8 inch wide wheel is as wide as it gets. So the same situation would lie in a 15 x 8 inch wheel with a 4.75 inch backspacing? What wheel would you guys recommend if a 15 x 7 inch styled steel wheel doesn't work out well with a 235/60/15 drag radial. Thanks

-Taylor
 
Bifs66 - What wheel/tire combination are you running at the track? What kind of wheel is your 15 x 8? Would the 15 x 8 '67 styled steel wheel work with stock drums in the rear? I have absolutely no traction in first or second gear from even a punch. Always appreciated.

-Taylor
 
So I called MustangsPlus and talked to one of the technical guys, and he did not have any information in the system on what the backspacing is. He said that he would guess that it is a 4"-4.5." I just don't know what to do at this point. Does anybody know where else I can find a 15" x 8" styled steel wheel?