Hey guys/gals, I have read seems like hundreds of posts and have not gotten the answer I need. Hoping someone has succeeded in doing this. So, here we go again. My 72 has 2" offset TA's with coil over upgrades with no leaf spring. I want to go to a 15x10 wheel. I'm sticking with the old school look and not interested in 17 or higher. What BS do I need to keep the meats tucked into the fender well?


Front 235/60/15. Back 275/60/15

 

I have American 200s 15x10s’ with 3” backspacing on the rear of my 69 with all stock suspension. Wheel rim to spring is my closest potential interference and that is 1”. They clearly fill the wheel wells but never had any contact with the fiberglass.

This picture was taken in June of 73 when I first bolted them on. Those are Goodyear Polyglas GTs - L60s. Today, I have Mickey Thompson Sportsman SRs 28x12s.

 

Thanks! That sounds positive. They don't stick out all all? I might be able to go with 15x12's in that case.

 

The outer edge of the tread is right at the plane of the lip but there’s about an inch of sidewall that goes beyond. Thanks to the geometry of the IRS, the tire fits in the well upon full travel. The tire to frame at full travel is close but I don’t recall the exact dimension and have never experienced any rub.

With your offset arms, you may be able to fit the 12” but the section width of the tire will likely play into the equation. If your supplier is willing to play ball, have them mount up a tire and see. I would recommend that you disconnect the coil over and run the suspension to full up to be sure no interference.

 

If you measure the width of the wheel well on my 69 it is 11 inches wide, from frame to inner lip. With parking brake relocated, no spring interference, and offset arms, the max backspace I have seen on these cars is 5.5 inches. So with 5.5 inch backspace and a 10 inch wheel, you should easily be able to get a 275 under the stock fenders, maybe even a 12 inch wide 295. As 69l88 said, the way the camber goes negative over a bump allows a tire slightly wider than the wheel well. Ridetech, which is the coilover system I have in the rear of mine, says you can do a 10 inch wheel with 5.5 inch backspace, and a 275 tire with their system. One factor which works against us 15 inch guys, is they have more sidewall bulge than the 17’s and bigger wheels.

The problem I found with 275/60/15’s is they are one inch taller than stock, so much easier to get it up in the fender if it’s close. I am running the Avon 275/55/15’s on the back of mine, which are stock 27 inch diameter, 11 inch section width, and they just fit on mine with 8.5 inch wheels with only 4.25 backspace. Eyeballing mine, it’s looks like I could make 5.5 inch backspace wheels work. I am going to have my wheels widened to 9.75 inches which will get me to 5.5 inches backspace, and when I need tires again, going to try a 295. Hope this helps!






Bill

 

I have never liked those rims... but dude... that is one SIIIIIIIIIIIIICK car...

 

Keep in mind those old L60's are not as 'square' on a 10" rim as a 295/50 would be. They are narrow. So a 295 would probably stick out a bit with his 3" offset. But... there are plenty ov guys running 295's on 8-10" rims here. I'd run that 295 with the same backspace, or very close to, as the stock 8" rim and all should be well. 4.25" to 4" backspace on a 10" rim should have those meats about flush with the lip. Get some and measure though... cars can have their own geometry sometimes...

 

I dug up some other pictures and measurements I took on the Polyglas GTs before I bought the M/Ts. The section width of the L60s was 12.1 inches and tread width 10.25”. The M/T 28x12s are about an inch taller but otherwise are nearly a dead-on match.

After 45 years, the Goodyear’s are retired (no pun intended)

Fresh rubber again.

 

I run 15x10 Weld Draglites on the back of my 80, and wanted the same flush with the fender lip look, but have given up on that. The MT 295 55 15 drag radials stick out exactly one inch past the fender, and I think it's the best I can do without rubbing the frame. I tried thinner wheel adapters to pull the tire in and they rubbed. So my effective back space is five inches....but the tires do stick out a bit