'71 GMC 2500 -- 8-lug wheel interchange.

[W. Higgins]

Hello all,

I've already searched the forum regarding this topic and can't find exactly what I'm looking for. I've recently purchased the above mentioned truck and, of course, it has split rims. I'm a purist and intend on keeping these wheels in storage but, for my current needs, I'd like to have a set of later tubeless wheels.

Does anyone know what later style wheel is back compatible with regard to diameter and offset and, hopefully, will still allow my hubcaps to snap on? Also, were 6-lug standard on 2500's at this time, making a proper 8-lug more difficult to find? I know on my '85 2500, such is the case -- it has 8-lug wheels (to which I would compare, but that truck is 1,200 miles from here).

Any help is appreciated. Below are some pictures.... just because everybody loves pictures.





Previous owner added the goofy steering wheel. That's getting changed soon, along with recovering the seat.

[67mater]

not sure what your interest is, but I have 5 original 8 lug wheels for a 68 GMC 3/4 ton. They are 16.5" which changes your tire options, but they ought to accept your hubcaps.

[stllookn]

Welcome to the board from Kent, WA. Great looking truck!

3/4 and 1 tons had 8 lug wheels...C20 and C30. Old school wheels were 16.5's but many other sizes were optional. 16.5 tires are a little more scarce today but still available at reasonable prices. I love the look of a big 33x12.5x16.5 on a 3/4 or 1 ton truck. I am keeping my stock 16-in. split rims for shows as well.

The widest stock GM wheel available for your truck was 8.25-in x 16.5-in dia. Those look great with a 31x10.5x16.5 or a 33x12.5x16.5 tire. I will post some pics later today.

[justcuz]

You can use 16 inch tubeless wheels and tires off of any 3/4 ton or 1 ton Chevy truck from the late 70's to the late 80's for a stock look.

I put the later model silver wheels on my 1973 3/4 ton 2wd Suburban, but need special aftermarket lug nuts to use the center caps.

You can probably safely run a 265/75x16 tire on that truck, maybe even a 275/75x16. A 235/85x16 is narrower but as tall as a 285/75x16.

Almost all 8 lug wheels are the same (except later model Fords) so you can use wheels from almost any manufacturer.

[W. Higgins]

To 67mater first -- thanks for the offer. I'll keep it under consideration, but I suspect the shipping would be killer. At this time, I'm mostly just looking for technical information. I can probably find whatever I need here locally.

Thanks for the compliment and the welcome, stllookn. I'd have no objection to 16.5's as long as I can get Michelin's for it. I intend to use it like it was intended, but it will have an easy life. I have a restoration business and want to use it as a shop truck and to occasionally pull an enclosed trailer. My thoughts are that if I get on the road far from home and need to replace a tire, I don't want to be stuck and searching for someone to deal with the split rims.

I'll study your 16.5 suggestion, and I'd also like to know if the 16" wheels (like on my '85) will work. They use a similar hubcap. That later 8-lug is a little more difficult to find, I think, because by that time 3/4 tons were standard 6-lug, but my truck happens to be one of the 3/4 "extra duty" (or whatever they called them) with heavier truck features to knock it out of the more strict EPA standards for the '85 models.

This truck is basically one owner (the guy I bought it from just bought it to flip it). The original owner purchased it to carry a slid-in camper. Aside from some bed floor rust, it's in excellent shape. Low miles, never driven in the salt, easy life, mostly original paint, blah blah blah.

[justcuz]

During these model years and up to 1988 no 3/4 ton had 6 lug wheels.
The 6 lug wheels on a 3/4 ton were only light duty 3/4 ton pickups.
Essentially they were a 1/2 ton with 3/4 ton rear springs and a 9.5 semi float 14 bolt rear axle. The front had heavier springs or torsion bars(4wd) but the brakes were 1/2 ton. The 2wd light duty 3/4 ton had a six lug brake hub/rotor assembly that replaced the 5 lug but the caliper and spindle may be the same as the 5 lug.

[W. Higgins]

Thanks for your comments, justcuz. I almost missed your first post, as you posted while I was writing.

I've been given the number of a guy selling a set of 8-lug Dodge wheels. Perhaps I'll give him a call since you mention most of them being the same. Are they also the same insomuch as the hubcap will still snap on?

[Longhorn Man]

If you plan on hauling heavy loads, then i would recomend sticking with GM wheels.
These trucks (and most any truck built) has hub excentric wheels. This means that the weight of the truck and load sits on the center hole of the rim, and then directly on the hub. The lugs just hold it onto the hub.
If you put ford or dodge wheels on there, then it becomes lug excentric wheels, and those lugs are just not designed to take the loads.
You can probably get away with the wrong wheels, even with carrying loads, but once you snap one lug nut, you are that much more likely to snap another, then another... well, you know where I'm going with that.
I highly recomend 16 inch rims. While there are still 16.5s avalible, they are getting fewer and fewer. (talkin street tires, no off road ones)
The 73 - 87 3/4 ton and SRW one tons would be the best source. There's a lot more of these wheels sitting around than you probably think, especially with your local tough inspection laws, the rusty 73 - 87s are getting scrapped daily.

[68,69 K20]

Originally Posted by Longhorn Man

The 73 - 87 3/4 ton and SRW one tons would be the best source. There's a lot more of these wheels sitting around than you probably think....

Yep, that's what I did to replace the split rims on my 69. Found 4 decent ones from an early 80's 1 ton(not dually). Check your local boneyard, seem to be easy to find around here.

[W. Higgins]

Originally Posted by Longhorn Man

The 73 - 87 3/4 ton and SRW one tons would be the best source.

Thank you, sir. This is the information I'm looking for. Now I know what specifically to look for.

[Longhorn Man]

someof them in that generation have 16.5's, so don't get ticked when you see it.
Also, I forgot to mention, your old hub caps will pop right on, and the offset/back space won't make it look funny.

BTW.. welcome to the board.

[justcuz]

Your 85 wheels or ones just like them will bolt right on. The hub centric issue is a good one. Fords and Dodges use Dana rear axles while Chevy used Eatons and Corporate 14 bolt full floaters. Not sure of the difference in the hub centers but they are probably close. For the record, I do not believe many aftermarket wheels are hub centric. Even though the lugs have fully sleeved nuts it stiil places all the weight on the studs and I have not personally seen a failure on aftermarket mag wheels. Just my 2 cents.

[Longhorn Man]

I have. Granted, it's only once in a great while, but they come into the shop like that.
About one or two a year.
The 14 bolt, GM eaton, and GM dana all have the same size hub. The silver wheels used on the 88 - 98 are too tight, even for the correct truck, it is not uncommon to need a sladge hammer to remove them, even if they've only been on for 6 months.

[justcuz]

Well you and him are in the rust belt, so Higgins take Longhorn mans advice.
We don't deal with the rust issue much here in the Southwest.

[factorystock]

Welcome, Looks like a real clean truck. Love the stance of your 3/4 ton. Looks like it can handle a load with ease. Early to mid 80's GM 16" wheels would be your best choice. I have seen many available, even with good original white paint!

[W. Higgins]

Thanks all, for the comments and advice.

Whoever made the comment about salt -- you're right. That's a problem up here that took me a long time to get used to. I'm originally from Arkansas.... I had stuff down there we considered junk that up here they covet -- which I never totally understood. Up here they'll take a badly rusted body and invest all kinds of money when they could just make a days drive south and find something better for way less total investment. It seems many just don't know. I lucked out with the '71, though.

I almost forgot, I also have this one:



But I just use it around my place down south. Nowhere near roadworthy anymore.

I wanted to post a shot of my '85, but turns out I don't have a decent digital picture of it. It's basically just the newer equivalent to the '71 (except the paint in '71 was way better quality). I, too, like the 3/4 ton stance, and believe that if you're going to use them for heavy work, you might as well own a heavy truck. I get so tired of 1/2 tons around here overloaded with the bumpers scraping the ground.

Fun forum. Thanks for all the welcomes!

[justcuz]

I agree! I am switching over to an eight lug guy my self. In fact I may convert my 71 1/2 ton long bed to a 3/4 ton. I have enough stuff laying around my place to do the conversion and could easily sell of the 1/2 ton stuff since that is what everybody wants these days. When I went to the Brothers show in Anaheim, it kind of hit me. There were several good looking 3/4 tons there, ones you could still use as a truck if needed. Couple of them with mild lowering that looked great.