Stock rim size for 1978 GMC K15 Stepside

[cromag84]

Hello all,

I just purchased a K15 that came with aftermarket rims and 33 inch tires. I’d like to purchase GM Rally wheels for the truck. Not sure the dimensions. 6 lug pattern.

Thanks in advance,

John

 

[dvdswan]

Welcome to the site.

The price depends on where you buy them from. 15x8 is factory for the truck IIRC. Trim rings come in 2 sizes; 2" and 3" or deep dish, the 3" ones are for the 15x10s IIRC.

You can find the rims on craigslist/facebook, prices vary on seller, your area and if tires are on them. New ones can be found at LMC but they're about 100 ea.

 

[77 K20]

They rally wheels were 15x8 for the 4 wheel drive 6 lug wheels.

I looked at car-part.com and found a place in Belchertown MA that has what looks like 5 rally wheels for $35 each. Might even come with the center caps and trim rings. The pictures show them on the wheels anyway. They were at Westover Auto Salvage. link

The wheels are off a 1985 Chevy Blazer- but wheels are the same as a truck.

 

[RoryH19]

Here's a pic of my 78 k10, as mentioned 15x8. They used the same through the 80s. I think you could still get them through 91 on the blazers and suburbans.

 

[AuroraGirl]

15x8 probably. 6 lug of course.

You must be registered for see images attach

I dont know if that is a stock wheel or not, but the same concept was the PA6 styled wheel option (wagon wheel from gm)

 

[cromag84]

Awesome. Thanks guys it’s been helpful

 

[78C10BigTen]

Hello all,

I just purchased a K15 that came with aftermarket rims and 33 inch tires. I’d like to purchase GM Rally wheels for the truck. Not sure the dimensions. 6 lug pattern.

Thanks in advance,

John

SWEET TRUCK!!! Stock ralleys and 33s would look better. I like the setup tho!

 

[AyWoSch Motors]

Hello all,

I just purchased a K15 that came with aftermarket rims and 33 inch tires. I’d like to purchase GM Rally wheels for the truck. Not sure the dimensions. 6 lug pattern.

Thanks in advance,

John

Stock, that should've had 15x8s.

Depending on the model or how it was ordered, you would've had your choice of steel wheels, white wagon spoked wheels, or ralleys. Ralleys are of course my personal favorite.

Mine with stock wheel..

You must be registered for see images attach

 

[RoryH19]

Stock, that should've had 15x8s.

Depending on the model or how it was ordered, you would've had your choice of steel wheels, white wagon spoked wheels, or ralleys. Ralleys are of course my personal favorite.

Mine with stock wheel..

You must be registered for see images attach

Also the 15x7 aluminum ones.
My 82 k5 had this from the factory.
Here is a pic at the paint shop

 

[AyWoSch Motors]

Also the 15x7 aluminum ones.
My 82 k5 had this from the factory.
Here is a pic at the paint shop

Ah yes, forgot about those. Those are a bit more rare. Did they offer those back as far as 78?

 

[RoryH19]

Ah yes, forgot about those. Those are a bit more rare. Did they offer those back as far as 78?

81+ for sure. Can't remember if they started earlier.

 

[78C10BigTen]

Ah yes, forgot about those. Those are a bit more rare. Did they offer those back as far as 78?

I had those on my 90' gmt400. I like those!!!

 

[RoryH19]

I had those on my 90' gmt400. I like those!!!

They are my spares, still have all 5.

 

[Rusty Nail]

Ya.
Look dude..
I'm thinking at stock ride height (your truck), a 15x8 in 33s may prove too big. Probably will in certain instances and since THAT IS the case, a 15x7 may be preferable.
Seems like it would be to me.... when dudes try to ride 33s over 31s they rub at stock height and run into issues.

Sure it will physically bolt up but it will rub on the away bar or the fender - whatever.

Heads up.

33s are the magical threshold size.
To successfully run 33s on 15x8s MOST folks add a +2 inch lift.
If not, they rub.
You likely don't have that trouble now BECAUSE the current wheels ARE!!! 15X7.

Thanks for the pics all.
Got any engine bay shot for bonus points?

Trade ya a tire fitment link......

Tire Size Guide – Does it Hit or Fit? – Offroaders.com provides information and entertainment to 4×4 enthusiasts worldwide

www.offroaders.com

 

[Grit dog]

^Rim width has very little/nothing to do with whether tires rub. Offset or backspacing has everything to do with where the tire sits in relation to the body.
You could have 20x12s with 33-12.50s or 15x6 with 33-12.50s and if the backspacing is 6” and 3” respectively, they’ll fit basically the same.

That fitment chart is handy though!