Hi Guys! Long, long time since I've signed on to this site. I got my 79 regal with a Chevy 350 when I was 17. I wanted to change the wheels since the day I got it, and only now that I'm 32 am I finally doing something about it lol. I would like to run standard body colored GM steel wheels with the poverty / dog dish center caps , 15x7 in front and 15x8 in back but I have no idea what the backspacing is. I have standard factory disk brakes up front and a grand national rear axle out back , which I assume is the same as standard g-body width. From there I don't know what tire to go with. I would prefer to stick with the tried and trueBFG radial t/a's for brand. Currently I'm running 14s, 205/70 in front, and 245/60 out back. I like that look and would like to do something similar with the 15s. So pretty much I need someone with knowledge of the 78-80 A/G- body to tell me what backspacing for the 15x7 and 15x8 steel wheels to buy, as well as the corresponding tire sizes. Thank You in advance!
235/60/15 is the correct height for G bodies. GNs had 215/65/15, and 215x.65=139.75. 139.75/.60=232.9 which is essentially 235. It looks like the factory 15x7s had 3 3/4” of backspace. So that should work on the front and you’ll want a little more for a 15x8 rear. When you swap in a 455 you may need different front springs. Patrick
I’m running 15x8 Trans am wheels on my 75 Regal. 4- 3/8" backspacing. I run 235/60R15 up front and 295/50R15 rear. Perfect fit and no rub.
So for the front I'm thinking these: 15x6 - 5x4.75- 3.75" BS https://www.jegs.com/i/Wheel-Vintiques/939/62-5634334/10002/-1 and rears these: 15x8 - 5x4.75 - 4.25" BS https://www.jegs.com/i/Wheel-Vintiques/939/62-5834044/10002/-1 Is that enough backspace for the rears? should I go more? also...why the hell are plain jane steel wheels so expensive and hard to find used!? lol
Also for tires I was thinking 205/60/15 BFG Radial t/a's out front and 275/60/15 Mickey Thompson ET Streets out back. good idea?
Steel wheels are cool now. Combine that with all the crushing and recycling that happened a few years ago (when they weren’t cool) and suddenly they’re scarce. I think your wheel choices are good. Personally I’d do 15x7 all the way around with the same size tire (235/60), but there’s nothing wrong with more in the rear. 205/60 is a short tire for the front though, you may have too much open wheelwell with it. Patrick
That’s more like it. 205/70 is 26.4”, vs. 205/60 being 24.7”. Patrick https://www.tacomaworld.com/tirecalc?tires=205-70r15-205-60r15
I think you will find that 275/60-15 is pretty wide under a ‘79 Regal. Its definitely NOT the same as a ‘75. Consider a 255/60-15 on a 7” rim