68 dually 1 ton rear questions

[qksilver]

New to the 3/4 and 1 ton trucks.
Bamm 24 has a coil spring 4.10 eaton rear that I am going to pick up next month. Plus there is 4.10 pumkin for sale on the board.
I have a 68 C-30 with a factory dually conversion
I am piecing together a 3/4 2 wheel burb from a 1/2.
The question is, because I can't get to the 68 where it's stored, will a 3/4 eaton rear pumkin work in a 1 ton dually rear?
Plus what gear ratio's were available? The 68 has something like 5.17 or higher, I want 4.10 in it and the burb I would like to run something lower than 4.10.
I like that the pumkins unbolt like a ford 9 inch rears, so I would rather swap that than the ring and pinion.
Any help would be greatly apreciated...........
Thanks,
Steve

[Fred T]

The pumpkin comes out by pulling out the axles and removing the ten housing bolts on the front. The only difference in the housings between the 3/4 and 1 ton is the housing width and brakes. Don't disassemble the carrier unless you know how to adjust the gear lash, the pumpkin swap is the way to go.

In the 10 bolt full floater, the best gears you will find are 4.10. There were a few with 3.73 and 3.90, but I have only heard of one confirmed find. Very rare. There were also 4.57 and 5.1x.

I have read on this site that a 14 bolt pumpkin can be used in a 10 bolt housing, but you need to find the right axle length as the 14 bolt uses a different count spline. You might try searching.

I would use a 14 bolt rear. 3.73 gears are an easy score, I have even seen some with 3.42s.

[Longhorn Man]

if they are both the eaton/corp rear, then yes, you can swap them right out.

[9footfan]

hey qksilver just wondering if you might be able to get a pic of the option sheet of that 68. we have had somewhat of an ongoing mystery here on the board about factory dual rear wheel conversions. we are looking for an actual pic of an option sheet with the dual rear wheel conversion rpo. thanks in advance and good luck with the project.

[Down south truckin]

Originally Posted by 9footfan

hey qksilver just wondering if you might be able to get a pic of the option sheet of that 68. we have had somewhat of an ongoing mystery here on the board about factory dual rear wheel conversions. we are looking for an actual pic of an option sheet with the dual rear wheel conversion rpo. thanks in advance and good luck with the project.

here's one off one of my duallys

[1969 GMC]

Originally Posted by Fred T

The pumpkin comes out by pulling out the axles and removing the ten housing bolts on the front. The only difference in the housings between the 3/4 and 1 ton is the housing width and brakes. Don't disassemble the carrier unless you know how to adjust the gear lash, the pumpkin swap is the way to go.

In the 10 bolt full floater, the best gears you will find are 4.10. There were a few with 3.73 and 3.90, but I have only heard of one confirmed find. Very rare. There were also 4.57 and 5.1x.

I have read on this site that a 14 bolt pumpkin can be used in a 10 bolt housing, but you need to find the right axle length as the 14 bolt uses a different count spline. You might try searching.

I would use a 14 bolt rear. 3.73 gears are an easy score, I have even seen some with 3.42s.

The 14 bolt does not have a "pumpkin" like an Eaton. You can swap the No-Spin back and forth between the carriers, or the side gears, but I do not think a carrier will fit. Even if it did, you would run into a number of problems, like fitting the pinion gear in the housing, and you'd have to set the gears again, anyway.

The 3.90 was aftermarket and pretty uncommon because they were very pricy, 4.11 is the highest you can go from the factory.

Swapping chunks is easy, but it'll probably be a mess with all the gear oil. take a couple of the lower bolts out and let the diff drain (they are through holes, not blind) THe 3rds are also heavy, around 135 lbs, so prepare in advance for that if you aren't the incredible hulk, lol.

[qksilver]

Where can I find out more about the 14 bolt swap?
I have 2 semi floating 14 bolts with 3.73'2
Thanks, Down South, it will be a while until I could clear around the 68 to get to the inside. In the process of cleaning up my shop.
The few who have visited know exactly what I mean.
Thanks,
Steve

[qksilver]

That answered that........looks like 4.10 is going to be the way

[9footfan]

thanks downsouth. is that sheet from a 157" wheelbase truck?