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Longhorn Man · 10-02-2009, 04:23 PM

Fred, welcome to the board! That is a beautiful 68 custom/20... don't see too many around that nice... esp up north.
The rear end in your truck is the Corperate rear. It is sometimes called the eaton. What it is, the eaton differental in a corperate axle, and is also called the HO52.
Wheels off of any 3/4 ton or single rear wheel one ton will fit up till 2000 or so. I think fords chainged a little sooner than 2000 though. There's a few things to consider on this however.
If you plan on hauling a lot of weight on a regular basis, then you'll want to stick with GM wheels. The center hole on the Ford and Dodge wheels are larger (and most aftermarket wheels too) and that is actually where the weight of the truck rides. Once you install a wheel with a larger opening for the hub, then the weight of the vehicle and load alll gets placed on the lug nuts. If you just use the truck as a daily driver and not for hauling/towing all the time, then you'll have no problems with an 'other brand' wheel.
Also, in 71, GM went to a larger wheel stud and lug nuts. 9/16ths up from a 1/2 inch stud. THis is actually not an issue. The taper of the lug nut centers the stud in the hole of the wheel, and it still holsds the wheel fine. I have personally been running my C/30 longhorn with later wheels since 2005, and one I had before that for 2 years also, absolutly no problems. If it bothers you, you can update the front end to disc brakes, and then swap in a newer rear end. (once you do a full brake job on this old drum/drum set up, you'll want to update for other $$$ reasons) Some have been able to redrill the hubs and install the larger wheel studs too.
On the stock steel wheels, you'll want to watch the back spacing too. It bothers some more than others, but the newer the wheel, the more back spacing it got from the factory, and the wheel gets placed further into the fender. On stock wheels it isn't a problem of rubbing, but it just looks funny to some.
The 16 inch non split rims on GM trucks started sometime in the late 80's to early 80's. They may have been optional sooner, but i am unsure. I do know my 78 parts suburban came with 16.5 wheels. You can allso find the wheels on vans too.
Don't be in too much a hurry, these wheels can be found dirt cheap, even free. I have personally given 6 or so 16 inch 8 lug wheels away, and have had at least 10 or 12 given to me over the years.
Junk yards and used tire stores are both good places to locate them.

10-02-2009, 04:23 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: 1968 3/4 ton rear axle hub size Fred, welcome to the board! That is a beautiful 68 custom/20... don't see too many around that nice... esp up north. The rear end in your truck is the Corperate rear. It is sometimes called the eaton. What it is, the eaton differental in a corperate axle, and is also called the HO52. Wheels off of any 3/4 ton or single rear wheel one ton will fit up till 2000 or so. I think fords chainged a little sooner than 2000 though. There's a few things to consider on this however. If you plan on hauling a lot of weight on a regular basis, then you'll want to stick with GM wheels. The center hole on the Ford and Dodge wheels are larger (and most aftermarket wheels too) and that is actually where the weight of the truck rides. Once you install a wheel with a larger opening for the hub, then the weight of the vehicle and load alll gets placed on the lug nuts. If you just use the truck as a daily driver and not for hauling/towing all the time, then you'll have no problems with an 'other brand' wheel. Also, in 71, GM went to a larger wheel stud and lug nuts. 9/16ths up from a 1/2 inch stud. THis is actually not an issue. The taper of the lug nut centers the stud in the hole of the wheel, and it still holsds the wheel fine. I have personally been running my C/30 longhorn with later wheels since 2005, and one I had before that for 2 years also, absolutly no problems. If it bothers you, you can update the front end to disc brakes, and then swap in a newer rear end. (once you do a full brake job on this old drum/drum set up, you'll want to update for other $$$ reasons) Some have been able to redrill the hubs and install the larger wheel studs too. On the stock steel wheels, you'll want to watch the back spacing too. It bothers some more than others, but the newer the wheel, the more back spacing it got from the factory, and the wheel gets placed further into the fender. On stock wheels it isn't a problem of rubbing, but it just looks funny to some. The 16 inch non split rims on GM trucks started sometime in the late 80's to early 80's. They may have been optional sooner, but i am unsure. I do know my 78 parts suburban came with 16.5 wheels. You can allso find the wheels on vans too. Don't be in too much a hurry, these wheels can be found dirt cheap, even free. I have personally given 6 or so 16 inch 8 lug wheels away, and have had at least 10 or 12 given to me over the years. Junk yards and used tire stores are both good places to locate them.