79 Caprice Classic Landau Rear Wheel Bolt Pattern

Why in the world does my '79 "stock", 305, metric 3-spd., one owner, Janesville Prod. # 336,xxx, never been wrecked, owned by little old lady w/ 79,000 original miles have a 5x4.5 wheel bolt pattern? Bad back and this cold is keeping me from getting the axle code (don't know if that will help). Scrapped two 15x7 stock rims by mistake and now I can't find any in these parts w/o spending a fortune online. Kept a pair of 14" 5x4.5 (cause they fit on the hub) thinking they where the 15" I took off to put 4 used Keystone Klassics on (great look til two split the seams on the inside and started leaking just months apart). Don't know size of housing but don't believe it's posi-trac. Anyone else have the 5x4.5 pattern on their Caprice and know how that happened?

Almost all of the B bodies from 77-90 are 5x4.75 unless it's a 9c1 with HD brakes then they I believe they had

the 5x5 all the 91-96 are 5x5 but my 79 Impala is 5x4.75(well 5x5 Axle swap in the rear but that's not stock

stock was 5x4.75) my sisters 78 Lesabre was 5x4.75.

GM never used the 5 on 4 1/2 bolt pattern on anything that I'm aware of except the early 60's Pontiac Tempest/Lemans and maybe the Olds Starfire. The 5-4 1/2 bolt pattern is common throughout the ford and Chrysler lines until you get into the larger cars and pickups.

That's what everyone with any knowledge of Chevy is saying! I am baffled why FOR SURE mine is 4.5. I just replaced the brakes and cylinders all for the smaller Chevy hub with no problem. Can't imagine the axles were changed. Must check axle code! Even tried to put 4.75 and 4.25 rims on and of course too big and too small. Just checked front wheel pattern and as suspected they're 5x4.5 also.

That does sound quite strange. Just to clarify, when you measure your studs, on a 5 lug, you measure from the center of the first stud to the outside edge of the opposite stud, not center of stud to center of stud. If you're still getting 4.5 measuring that way, then we are going to need to see some photos of your front and rear hub assemblies. As has been stated, 4.5 was used in the 60s, but today, you find 4.5 on Mustangs and Rangers of the 80s and 90s. Almost all rear-wheel drive GM from 70s-90s are 5x4.75. I can go outside right now and take off my 1989 Firebird wheels and bolt them right on my '79 Caprice. It would look funny though.

Well, what do you know? I always did the center to center way. Man, you are saving my days! It is 4.75 that way. I feel like an idiot now after all these years working on cars and didn't know that. I guess these junk yards around here don't know that either, when I tell them center to center they don't even question it. So the two wheels I borrowed were 4.5 & 5. This is going to make it alot easier to find rims and get rolling again. Hope others read this and get it right, too! 10x THANK YOU.

https://www.gmbbodyforum.com/t89-what-size-wheels-will-fit-on-our-cars

mylilcaddy wrote:Well, what do you know? I always did the center to center way. Man, you are saving my days! It is 4.75 that way. I feel like an idiot now after all these years working on cars and didn't know that. I guess these junk yards around here don't know that either, when I tell them center to center they don't even question it. So the two wheels I borrowed were 4.5 & 5. This is going to make it alot easier to find rims and get rolling again. Hope others read this and get it right, too! 10x THANK YOU.

Thank goodness, for a minute there, I was thinking you had some strange setup. I had a feeling the way you were measuring might have been the reason though. A lot of people probably aren't aware of the correct way to measure 5-lug. It's the exception because no two bolt holes are directly across from each other from center of hub. You should have no problem finding wheels to fit that car. There are literally thousands to choose from!

And a simple AMEN to that!