70 k/20 14 bolt swap questions and concerns
 

Im sure this question was asked plenty of times. But i have a 1970 k20 chevy pickup with eaton ho52. Well today is decided to take a crap on me. so the 14 bolt dually rear i have is going in this weekend. (pretty sure it has 11.5 ringear). Any how i know you have to cut the spring perches and shock mounts. thats no problem. My one concern is will the back driveshaft on the eaton work on the 14 bolt? Any other questions, pointers, or advice is greatly appreciated thanks Collin.

Re: 70 k/20 14 bolt swap questions and concerns
 

Just curious, what went south in the Eaton?

Re: 70 k/20 14 bolt swap questions and concerns
 

Axle broke.

Re: 70 k/20 14 bolt swap questions and concerns
 

i have heard eaton rears can swap the axles and spider gears with 14ff axles .

and 14ff were 10.5 ring gear . latter 11.5 were aam axles if i recall correctly from 00ish up trucks .

Re: 70 k/20 14 bolt swap questions and concerns
 

When I put in my 14 bolt in my 72 K20 I used the same drive shaft. My suggestion when you weld on the perchs have the axle on the truck, set the pinion angle, tac weld, then remove and weld up. I didn't have a big enough welder in my shop, so I went to our main shop and welded them on. I went off the angle of the original perchs, not a good idea. I think my angle ended up being off because the springs are different lengths on earlier models. Don't quote me on that but that is all I could come up with. Luckily I was able to shim it 6 degrees to get the proper angle. I could have avoided a $50 bill.

Re: 70 k/20 14 bolt swap questions and concerns
 

On my swap from HO52 to SRW corp14 I came up about 1/2" shorter yoke to yoke using zero rates on 1" setback. I made no drive shaft modifications. And definitely, dial in the perches for the pinion angle if you have to weld perches. But just for info sake, a one ton SRW corp14 will bolt directly into the K20 with only shock tab relocation. If you have a line on one of those with the right gears its a quick job.

j

Re: 70 k/20 14 bolt swap questions and concerns
 

Good luck on your project. If you get a chance please check out my WTB ad, as you may be pulling off stuff I need
Thanks, Tom

Re: 70 k/20 14 bolt swap questions and concerns
 

ok thanks everyone for the advice. it is going to be this weekends project.