The Stovebolt Site Forums The Parking Lot '60-'66 Trucks 3/4 ton to 1/2 ton conversion

I have a 3/4 ton '66 chevy that currently has 8 lug hubs and an inline 292 mated to an sm420 trans. I also have a '66 1/2 ton parts truck with 6 bolt hubs, and I was wondering if I can swap out front end parts to convert it to the 6 bolt pattern? Also, I would like to keep the rear end I have in the truck, is there any way to modify it to use the hubs from the 1/2 ton? I thought about just changing out the rear ends completely, but then I have to use the 1/2 ton driveshaft (it's not in very good shape) and switch to the 3 speed overdrive trans from the other truck. Any ideas on converting to a 6 lug without replacing my trans and driveshaft? Thanks

What's wrong with the 3/4-ton? I mean, why do you want to change to 6-lug hubs?
Just curious...
cm

I want to change them out because aftermarket 6 lug rims are so much cheaper and more readily available, and I'm not a fan of stock steelies.

My thought is that you are going to spend more changing over to the 6 than what a 8 lug rim will cost but it is your money. There are sum after market hubs that might work. But i have never seen a heavy duty rear end with 6 lug so i dont know about that. Good luck with it.

i'm doing the same thing myself, if i understand correctly (i havent undertaken the project yet...) the parts will swap over, the big difference between the 1/2 and 3/4 tons are the spindles and rear axles, but the parts are interchangeable. like i said though, i havent gotten into the project to say for sure either way...

Spindles will not swap. Or at least not without swapping the control arms and balljoints first.
If you want 6 lug on the rear, you're going to have to swap the entire axle assembly. The 8 lug rear has no interchangeable parts with the 6 lug.
How far gone is the 1/2 ton? You may be ahead to restore it rather than the 3/4 ton if 1/2 ton is what you really want.

The half ton is complete, but it is pretty far gone. My original intent was to fix it up anyway, until I found my other truck on craigslist listed as a parts truck and was able to buy the whole truck cheap. The one I have been working on is in much better condition, it only rust on (through) the floor and front cab supports, which I am almost done fixing, and the bottom mounts on the front fenders rusted out. Aside from that, the entire undercarriage and drivetrain is in good shape and amazingly clean, not even surface rusted, whereas the 1/2 ton is pretty crusted up, and some of the suspension parts are shot. As far as swapping front end parts goes, I can do that easily, even if it requires drilling new holes or fabricating brackets. But, if there is no way to convert the rear end to 6 lug, I guess I will just have to stick with the 8's for now.

I've seen plenty of aftermarket 8-lug rims on the "off-road" trucks around here...chrome, alloy, etc. Those mud runners like the HD axles and huge tires. You might look at Summit, LMC, etc.

cm

What is the ratio of the 3/4 rear, are you going to be able to cruise down the hiway at a reasonable rpm, the ratio's on the 1/2 ton's are a little more flexible. just a thought.

I've looked into rims from Summit and a couple other places, I found some reasonably priced rims... I still can't afford them right now (thanks to college tuition) but I should be able to pick up a set at some point.

As far as the gear ratios go, it has 2.73's in it right now, and fourth gear in my trans is 1:1, so it should be fine cruising. I also have a set of posi 4.10's that I want to put in eventually, when I have the money to make it into more of a drag truck, but that's a ways out....

I got an idea this weekend when I looked at my dads f-150. Here's a link to a picture I found that is basically the same thing
rear end pic
That got me thinking, would it be possible to pull the yokes off of the two rear ends, and modify the 3/4 ton one with a similar plate design to fit onto my 1/2 ton? I would need the back end of the 1/2 yoke, with the original splines to mate to the gears... being the shaft the yoke slides onto on the 3/4 ton is bigger, putting the 1/2 ton yoke onto the 3/4 would be impossible, but 3/4 to 1/2 should be possible, right? I would just need to connect the bigger yoke to the smaller splined piece vis a sturdy plate. Then I could switch rear ends, without ditching my driveshaft or trans, and would be able to lighten the truck and get my 6 lug rims. Think it could work?

That's alot of work, and it would have to absolutly precise to prevent vibrations and part failure. You might be ahead if you want to us the 1/2 ton rearend to see if you're local parts store can get you a U-joint with 2 different size caps, 1 sized for the 3/4 ton driveshaft, the other sized to fit the 1/2 ton.

Thanks Bill, I hadn't thought about that, I'll do some checking and see if I can get a U-joint like that.

You might try Napa. I used to run around with a guy that had a 49 1 ton. We swaped the Eaton out for a Dana 60 out of a Dodge van, and that's where we got the dual size U joint.

I have the 3/4 ton also. there are some nice aluminum rims brand new that I see listed on ebay all the time for less than $400 including shipping. There brand name, but I don't remember what brand. Used 16 inch tires are easy to come by. More than likely some unforseen problem will come up in a swap that will cost you more than that. Also if it has the dana 44 with posi (so slip as the called it back then) I think you want to hold on to that. Thats what mine has and I remembet hunting for them back when we were building mud trucks up north.

I understand the money thing. It all takes time but iam sure it will be a great truck when you get done. Realy like the truck in the back ground. Love that color.

Thanks, it's been a fun project so far, and we've been able to keep the cost down pretty well.
The truck in the background is the original truck my dad got from his uncle's back 40. I was going to fix that one until I found the blue one and decided it was in much better shape. Now dad's has become a much needed organ donor
At some point I would like to fix that one up too... but that has to wait until I have a LOT more money