It depends on the back spacing and width of rim you use. 15" wheels never came on a 1969 A body as near as I can tell. On a 7" wide wheel, I say you need 5" of back space minimum to fit the widest tire possible. I base my conclusion on the Rallye wheel chart in this Forum. The 1968-70 14 X 6" wheel has 4 3/8" of back space. A 7" wide wheel would need 1/2" more back spacing to center the wheel/tire as stock. That's 4 7/8".
I have 15x7 with 4” backspacing and bf Goodrich L60’s on the back of my 69 skylark. No issues, I think it’s similar to a 275/60/15 but the L60’s are an inch shorter.
Mark, have you actually measured that back spacing? That contradicts everything I know about back spacing requirements for the pre 1970's cars. No stock 15 X 7" wheels had 4" of back spacing, so those wheels have to be reproductions. I don't understand how they can fit with L60-15 tires.
The L60-15 has a section width of 10.50"(266.7mm) and a tire height of 27.86". A P275/60R-15 has a section width of 275mm (10.8"), and a tire height of 27.99". The measurements can vary a small amount depending on the rim width they are mounted on. So an L60-15 is actually a little smaller by the numbers. It may appear bigger because of the overall tire construction. The G60-15 has a bigger look than the P245/60R-15 even though they are very close in measurement.
They are reproductions Larry. 15x7’s from Coker tire if I remember correctly. I’ll pull one off and measure it again this weekend.
I have 4ea 1970 Buick 15×7 WG rims with BFG 245/60-15's on my 69 convertible. No issues whatsoever!It's 4-3/8" backspacing.
I had 275/60 rears and that was a bit too much, tight quarter lip clearance. Went to 17x9 with 275/40 and have more clearance now due to proper backspace/offset
68 & 69 unique body style is well suited to wide back tires and stock size on front. Makes them look really tough. That's the 1st thing I would do on any 2 door model stepchild.
I have 245/70/15x7 4.5 back spacing on my 68. About 3/4" from lip. Edited to add my post is likely irrelevant since I put in a 10 BOLT 8.5 1971 Olds A-body rear end. (monzaz build) Thanks Larry. Apologies.
I have 275 x 60 x 15 on one of my 68s and on my 69. Stock Buick mag wheel. 15 inch diameter and 7 inches wide. I don’t know the backspacing but I believe 68GS_400. I’ve never heard any scraping or felt any scraping or seen any scraping.
I got Hoosier DR2's for the track. I cut some lip out, but still have some slight rubbing on sharp turns.
Everything I have ever read about tires on the 68-69 says the wheels need more back spacing than the 70-72. Some of you may be getting away with it, but it is far from optimal. To fit the biggest tires, you need to center the wheel in the wheel well. 4 1/2" on an 8" wide wheel is NOT enough. Have a look at the 65-69 14" wheels. They were 6" wide. They used 4 3/8- 4 1/2" of back spacing. A 7" wide wheel would need another 1/2" of back spacing to keep the wheel centered. That's 4 7/8- 5" of back spacing. An 8" wide wheel needs a full 1" more back spacing. That is 5 3/8- 5 1/2" of back spacing. https://www.v8buick.com/index.php?attachments/wheelchart-jpg.158600/
Might depend on what rear end is in Mark's 69.. the 65-7 A body rear ends were 1" narrower overall. Pretty sure that includes the 10 bolts, for sure on the 12 bolts, because I owned and used one for many years on the 70 GS race car. Mine was from a 67 Chevelle SS396 that was wrecked in the mid 80's. I Specifically found and installed that rear end so we could maximize our tire size with the Centerlines we had at the time. Complete, very good condition 12 bolt Chev with 4.11 posi from the factory.. paid $400 for it.. found it thru a classified ad in the Sunday MPLS Star/Tribune. Those were the days.. JW
I've got 275's on. 10" tread width 12.7 section width. I only cut the fender to the trim. So 1/4". But they fit