Hey guys another quick question what is the biggest rim I can put on my 72 skylark I like the wide wheel look in the back I was thinking some 15 x10 was just curious will this fit I could get 15x8 but if I can fit them I might as well get the bigger rim and what would b a good size drag radial to throw on them thx open to all suggestions Oh an I'm just going to run 15x7 in the front
Those rims you want will not work. You need 5 1/2" of backspace. There's been lots of trial and error here with 10" rims......they need 5 1/2" backspace.
Got cha so if I want 15x10 I have to get the 5 1/2 backspace and if I run with the 15x8 the 3.75 would do got cha thx again I have to check an see if they make them in that size I'm shooting for the American racing silver outlaws
No, you have to have the correct back spacing or you will have problems. The 10" wide rim can require 5 1/2 -5 5/8" back spacing. The 8" wide rim will want 4 1/2" back spacing. You want the rim centered in the wheel well. Sometimes, the body is shifted on the frame, so you might have a bit more room on one side, and less on the other. The 8" wide rim is the safer bet. It will fit easily. The 10" wide rim is getting very close to the limit, and may take a bit more work to get it right. Phil Sedlon (70 gsconvt) did this way back when. This thread has more information. http://www.v8buick.com/showthread.php?15046-My-new-new-15x10-s-are-here!!!&highlight=
I've had them all on my car up to and including my current 15x10 with 5-5/8" BS. You can squeak by with a 15x8 with the 3.75" BS, but you can't put a big tire on it. For a 15x8 to be centered in the wheel well, you need 4.5" BS. The 15x10 can accommodate a 295 tire no problem. I have a 325/50R15 tire on mine. That does require rolling the top of the fender well lip to assure no rubbing. And it's close on the inside. I can barely stick my finger in between the frame and the tire. I'm actually going to be putting a 1/8" spacer to give me additional clearance. Also, with tires that big, you may want to seriously consider airbags in the rear springs. The inside of the wheel well is rounded, not shaped for a tire. So with people in the back seat or a big bump, the tires can rub up in there. The airbags just at 7-8 lbs of air pressure will take a lot of the bounce out of the back while still maintaining a decent ride and prevent most problems. Just remember that each of these cars are slightly different in the rear. They weren't built to exacting standards back then and they do very up to 1/4" either way. Mine is off center just over 1/8". That's why I'm going with the spacer on one side. Good luck. UPDATE: I checked American Racing Outlaw I and II. The only one that would really work is the 15x10 with 6" BS. You should be able to put a 295 tire on there and have it work.
Thx guys for the input definitely helped out a lot I noticed the outlaws didn't come in that size I just really like the old school look and they were cheap 100$ each so I type in specs on summit an found some centerlines that look identical I think they were 160-180 a piece but I would have been way off if I just bought the outlaws so thx thx thx again I just can't have fun with this big wheels I have now what a waste of money: ( thx again guys I love this site
I too have a 72 skylark I was thinking about putting 18" wheels in the rear with 17" in the front. Does that effect the required backspace or the width at all? Or would does the rim height not make any difference? Also, does the front wheel require the same backspace as the rear of 5 1/2"?
This was on my car, 17" Pro Touring Wheels / Rear 17 x 9.5" Billet Buick Rallye Wheels 5.5" Back Spacing Pro Touring Wheels / Front 17 x 8" Billet Buick Rallye Wheels 4.75" Back Spacing
The diameter of the wheel makes no difference. You'll just need to adjust your tire's aspect ratio to make up for the increased size. The overall diameter has to remain the same. The wheel well is only so big and will only accommodate so large a tire before you start to have to lift the whole body up and now you're "donking" your ride. The larger diameter wheel/tires actually have a larger contact patch on the road. That's probably why so many people go to them, even the factories.
Like Phil stated, back spacing is required to center the wheel in the wheel well, so you have equal clearance on each side of the wheel, and you can fit a larger tire. The wheel width dictates the back spacing, so back spacing changes with wheel width. All this is well documented for the 70-72 Skylark/GS on this site. A 7" wide wheel needs 4.25" of B.S., an 8" wide wheel needs 4.5", a 10" wide wheel needs 5.5-5.625" of B.S. This applies whether you have 13, 14, 15, 16, 17", or whatever size wheels. As the rim size gets bigger, you need a shorter side wall to keep the overall diameter of the tire/wheel within limits, generally 26-28". You can fit wider rims and tires at the rear. As you go to wider tires with bigger section widths, you need wider wheels to keep the tread flat on the ground and to keep the tire stable. An 8" wide wheel is plenty for all four corners of the car. Again, you need 4.5" of B.S. on an 8" wide wheel. In the back, you can go to 10" wide wheels, but that is pretty much the limit, so things get close. On older cars, the body can be shifted a bit on the frame, so clearance can vary a bit on either side of the car.
What is the widest rims and tires i can use with 20" wheels i would like 275 rear and 255 front 10 rear 8.5 front can it be done and what back spacing would you recomend
It doesn't mater whether the rims are 13" or 20", the back spacing requirements are the same. The back spacing needed will depend on rim width. The 70-72 Skylark/GS has some generous wheel wells. Most guys go with an 8" wide rim, and 4 1/2" of back spacing works great. You can run a 10" wide rim in the rear, but you are very close to the limit there, so things like body position on the frame come in to play. You can have slightly more/less room on either side. The guys running a 10" wide rim are using 5 1/2- 5 5/8" of back spacing. A 275 tire in the rear, and 255 tire in the front is no problem at all. If you want to run a 10" wide rim in the rear, I advise doing some careful measuring of YOUR car. Can't really do much better than that.
I have a 67 Riviera with a pretty big wheel well front and back can i fit 20x10 285/30 in rear with a 5.5 back space 19`s in front 265
