Good morning everyone, On the rear of a 1965 Skylark, could you run P275/60R-15's on a 15x7 rim with 5 inches of Back Spacing or would it be safer (better), to run them on 15x8 rims? The reason I ask this question is that it is easier to locate and cheaper to buy 15x7's than it is to get a pair of 15x8 rims. I understand that the key is the 5 inches of Back Spacing, so that alone makes both rims harder to find than a rim with the standard BS of 3.5 to 4 inches. Anyway, I would like to hear all your input (experience, good and bad), on this subject! Thanks, Doug
Hi Doug, It really is best to use a 15x8 rim with that tire only because it will help give you a better contact patch on the pavement. When you use a wide tire on a narrow rim it makes the sidewall balloon out but also makes the thread surface balloon as well reducing the pressure on the outside of the tread. As a kid I once mounted a set of 295/50R15 on 15x7 rims and I found out that not only did it look silly it also wore out the center of the tires first and the outside of the tires was barely touching the ground when doing a burnout. There are racing classes that limit the tire size to 275 width and those guys use 10 inch rims to spread out the tire and give it a full flat width and contact patch. Here is an example of my chassis dyno rims and tires, 295/50R15 on a 15x12 rim because I wanted a nice wide flat contact patch on the dyno rollers. And here are pics of the same tires on a 15x7 rim.. NOT my car:
Sean, Good info, I figured a 15x6 would be the one to stay away from but, thought the 15x7 would be close. I've seen 15x8.5, 15x9, and 15x10, so I guess I'll continue looking at 8 to 10 widths and see what I can come up with that doesn't require modification to the rear end, frame, and anything else. It's easy to understand why mini tubs are so popular! Thanks again! Doug
Yep, just that a 1965 Skylark Sport Coupe, or Hardtop Coupe depending upon who you ask. It's the 355 Wildcat, ST300, just a plane old Skylark. I'm still kicking around with which engine (a 73 350, or the 69 400), with TH400 to put in it. I've even looked at a few cool LS swaps. Lately, looking at the 8.5 rear for a swap. Why do you ask? Doug
Just curious how much room you had in the wheel wells... I know in my old 70 Skylark I had 15x10 rims with 12 inch wide tires in the stock wheel wells but your car wont fit that much tire i would think.
A 275/60-15 is the biggest tire that will fit under the fenderwells on a `65 Skylark so you have to be very careful with backspacing. I have 8" wheels on mine the I still had to do a little bit of hammer work on the outer wheelhouses. 5" with a stock width rearend is perfect. In my case I have a `70 rearend under it, which is 1" wider overall so I am using a 5.5" backspace. If you have your heart set on a 7" wheel with a 5" backspace you should be fine, or even a 4.5" backspace on a 7" wheel should work but if you have to buy wheels either way, I'd go with the 8".
Thanks Jim. Last year I swapped to steelies and dog dish caps because I felt I needed a change. Same size wheels and tires. I had the wheels built by Wheel Vintiques. Also removed the cowl hood. Now I'm not so sure I like the sleeper look as much as I thought I would and recently picked up a set of Torque Thrust Ds on craigslist. I'm trying to get used to that new look now but am almost swaying toward going back to the Pro Stars. Anyway, here are a few pics that will give you an idea what an 8" wheel and 275/60 tire look like mounted on a `65.
Bill, I love your car, the stance is dead on and any tire and wheel combo you have on it always makes it look killer. That is the look I want to achieve. Your car is perfect, I want it, and call "First Dibs" if you ever decide to get rid f it! Doug
I'll let my wife know. Until I die, nobody gets it, and I'm only 62 so it might be a long wait :grin:
