I'm looking around and doing research in anticipation of a disk brake upgrade. Ideally I'd like 17s but would consider 18s. As I understand it 4.5" of backspacing is about where I need to be. I'd love to be able to fit some 255 up front and a 275 rear. 275 square would be good too but not a deal breaker either way. Theres some info here and there and I think my plans would work but I'd hate to buy the things and they rub or not fit altogether. Does anyone see any issues or potential issues here? My time frame is probably Jan - Feb
For reference I was thinking about something like this http://www.ebay.com/itm/CPP-US-Mags...ash=item20fa1c3acb:g:F2wAAOSwv0tVKjdd&vxp=mtr
I have the American Racing VN500s on my 65 Skylark. Fronts are 17" x 8 with 5" backspacing. I have Nitto 555 17ZR245 on them. I had the 255's on there but ran into some rubbing issues with the 5" backspacing. I would have needed a 5.25" backspacing to clear using the 255s. I also have the 11" disc brake conversion on the front. That would have to be factored in. On the rear I am running the same Nitto 555 but with the 17ZR285 tire. The wheels are the American Racing VN500 17" x 9.5" and 6.375" back spacing. However I am running the 1971 8.5" rear axle which is 1" wider than the stock 8.2". So you would have to subtract .5". Now we pushed out on the rear wheel well some to gain additional clearance. Also did some work on the inner fender well to make it about even with the frame. I believe I have enough clearance to fit a 295 tire if I wanted. One more thing I also have the disc brake conversion on the rear. Not sure if any of this will do you any good as mine is not exactly stock with the disc brake conversions and the Buick Skylark 71 rear axle. Edit: added a couple of older pictures. The one on the right shows the clearance on the rear and you can see we rolled the outer rim some.
I have a thread I bumped it up to the top. On this topic bro. I can't get a link to work foro m my cell for some reason.
Joe may be referring to this thread. http://www.v8buick.com/showthread.p...t-More-Than-a-9-in-Tire-Back-There&highlight=
1989GTA, your setup is close to what I'm after. Very nice build BTW, I've read a lot on it. I'm really not trying to put the cart before the horse on mine. Not that my funds will really allow me to anyways. I've got to figure out brakes, ride height and wheels/tires.
4.5" of back spacing on an 8" wide wheel is perfect for the 70-72 Skylark/GS. The 65 cars need more back spacing, more like 5".
I looked up some 275 x 17 tires and the minimum wheel width they recommend is 9". 9.5" is ideal. Something to think about.
275's are pushing the limits of the '65 wheelwell. They'll fit but wheel offset has to be near perfect (+/- 0.5") If you are putting disks on the rear, that may push the wheels out even further. Some 64-67 GM A-bodies used a narrow rear ('64 Olds, 12 bolt Chevelle), some are 1" wider (GTO and Skylark). There are wheel fitment tools out there, that's almost a necessity in your case. Anything else is just a guess. Wheel spacers can be used to make a small adjustment to move the tire out, but there's no way to move a poor-fitting combo inwards..... although you could have the rear narrowed.
Well, I think I've got a direction of travel figured out on some of this. After some research I'm going with a set of machined hubs and brackets that allow me to run a disc brake setup off an LS1 F body 1998-2002. That'll give me 12" rotors up front and two piston calipers without changing the track much if any at all. I can run the same on the rear but still need a bit more research to see if it pushes the track out any and figure the parking brake out. As for wheels I'd like to stay with 17x8 square, probably a 245/40/17 tire
Placed an order today. Pics, specs and info to follow in about a week. Went with US MAG U109 Bandit in 17x8
Upgrade the brakes first and then start measuring. Otherwise you're just guessing and could be making a very expensive mistake. I have a 64 with a slightly narrowed 12 bolt and it'd be real tight fit with 275's in the rear. Right now I have 255's on 16"x8" rim with 5" backspacing. The shock mounts could be a restriction unless you go to a 16"-17" rim. Up front I have 16"x7" rims with 4" of backspacing and run a 225 tire. The car has lowering springs and the clearance is pretty close. I have an aftermarket disc brake kit that pushes the mating surface out about 3/8" on each side but some aftermarket disc brake kits maintain the same track as the drums. That's why you have to install the brakes first and measure.
Here's a thread from when I put 17's on the 65 GS. I do not have disc brakes though. http://www.v8buick.com/showthread.php?297756-New-wheels-on-the-65&highlight=