I'm looking at running an 18" rim on the 71 Skylark I just purchased but I'm unsure of the minimum backspacing I can get away with without fender lip modification. I'm looing at 18x9.5 or 18x10 rears the most common ones I can find are 5" backspacing will tis clear my 295's or do I need 5.5" backspacing? I've seen guys running 18x10's with 305's with 5.75 but I don't want to buy something that wont fit. thanks
Any idea who makes rears with 5.5 I was looking at the Boss 338 but the backspacing only goes to 5.03 I want something along that line but can't throw me than $800 on rims, the ol lady would kill me.
The 5.5" of backspacing will center the wheel in the rear.....for the most part. These cars are not all alike. But if you use a 305 or narrower tire, you should be fine. Most companies do not make this exact BS. But most manufacturers will make them for you, for a price. Good luck.
I'm looking at running a 295 45 18 in the rear I bought them for my last project and never installed them they're just sitting in my garage in bags, I'd like to run these on a coy c5 but they don't offer the backspacing I need without custom ordering them (way to expensive). so I started looking at other companies and it seems most companies only make a 9" rim with 5.25" backspacing. do you think I can squeeze the 295's on the 9" with a 5.25 back spacing without running into issues? Nitto suggests a minimum of 9.5" for the 295's but o my jeep 35x12.5 required a minimum of 9" but they ran fine on my stock rims no issues with wear etc. Do you think running a 295 on a 9" with 5.25 would have any reason for concern?
I ran a 275 on an 8" wheel for a while. It's OK, but the tire starts to look a bit bulgy. As for the spacing, I think you'll be OK as the 1/4" less BS is working with a 30mm narrower tire. That's a bit over an inch, so half of that is just over 1/2". Wow. I just read that back to myself. Lots of math and could sound confusing.
I despise math but usually i can figure things out, however this is my first A body car and I'm not looking to make $1000 mistake buying the wrong rims. thanks for all the help.
The best thing you can actually do is to put a wheel/tire on the car, put it on the ground and start measuring. Then you'll know for sure. You may be able to get a crap tire from a tire store that's near the size you're looking for free. Remember, it's not the wheel size that's the critical thing here, it's the overall diameter and width of tire. Good luck.
you can't just read what others are running, Your brake selection makes a difference too, I have a 71 with 18" 295 back and 255 front and didn't roll or modify the lips, The boss 338 with standard back spacing will not fit if you plan on turning corners I have a new set with rubber if you want to buy them. I'm sure my backspacing is over 6"
The rims are 18x8 front (4.5 BS) 18x9 rear (5.25 BS) drums all the way around currently will be swapping drums out this fall. I've decided to buy the US MAG Bandits instead of he BOSS 338's because the backspacing is better, worst case I roll the rear fender lip if it is an issue I guess.
The firtment I'm concerned with the most is the rear end. Yeah I've read that the mounting face on disc brakes vs. drums makes a difference. Worst case I run a small spacer to clear control arms. Thanks for all the help everyone. I am ordering the US MAG's tonight should have them by mid next week, I'll post pictures of the test fit then hopefully by Friday I'll have them mounted and then I'll add some more photos.
So far so good on rear clearance now I just need my tires mounted. Hopefully Tuesday i'll have finished photos of the whole car.
Nice looking wheel. Those 295/45 tires are going to be pretty tall (I ran this size Nitto 555 for a while). You will need some drop springs in the rear to make it sit right, especially if you have dropped the front any.
Should sit pretty low back there due to the rear coils being worn out, I like a little rake to my muscle cars hoping that they don't scrub on the inner fender wells when driving down the road. I may need to replace the rear coils sooner than I hoped. I have new coils to be installed in the front because those are pretty bad too but I'm trying to wait till the fall before I put her away for the winter. That may change if they rub really bad. Currently it's sitting on 215 60 15 Keystone Klassics which is roughly a 25" tire so my headers drag on bumps in the road.
Well I managed to get the rear rims on they fit great with the 295 45R18's no rubbing issues at all. I did opt to roll the lip about a 1/4" just to be on the safe side. I had about 3/16" clearance to the fender lip and wanted a bit more incase the axle shifts while driving. plenty of clearance to the frame rail could easily squeeze a 305 in there with a little more backspacing here are a few shots I managed to get last night in the snow
After a disaster with wheel studs "thank you Dorman and previous owner" I have the rims all on. Got to be happy the wife didn't try and kill me over the past 2 weeks while I was trying to get this all completed. Next year a 4 wheel disc conversion and hopefully new paint to fix the minor issues and get rid of that damn stripe. Wheels are US MAG Bandits 18x8 w/235 50's up front and 18x9 w/295 45's out back. Nitto 555's
Thanks very much and no problem I spent so long looking for specs and what would work I figured I would try and help out a little from what I've learned Here are some better photos
