Dana 60 to Dana 70hd?

[Thanos]

Hello I am new to forum (member) however I have been reading it for years on and off hoping to one day own a classic.

I finally bought a mint condition 72 GMC with 50k originally miles out of AR (no rust yay!)

So it's a 3/4 ton long bed version, long story short just want to swap the d60 for a d70 HD I already have. Perches I noticed both measured 42 1/2 or so it appears...

The pinion measure same also.. is this a straight swap or does it require more?

[1972RedNeck]

I'm betting the pinion on the 70 is longer but I don't know for sure. Tape measures don't tend to lie...

[Thanos]

It measures the same across the pinion "block" ? that accepts the U joint. I haven't gone from there yet.Supposedly the pinion on 60 and 70hd are the same "some" people claimed.

The thing worrying me at the moment is the mounting plate the U-Bolts go into at the bottom considering it's a 4" tubing on the 70 HD.Thought maybe grind it,find ones for a 70 or ...

[Thanos]

I find it hard to believe however I assume I am the first person to do this kind of project?

[kwmech]

When you do things like this, nothing is a ''straight up swap''. You are going to need u-bolts, different u-bolt plates, shock mounts will be different. You may have to get a degree shim to roll the pinion where it needs to be. You may even have to play around with the parking brake cables to get the lengths correct. The driveshaft will have to be shortened.

I put an HD in my flat bed and currently have one in a frame build up I am starting

[ERASER5]

I swapped from a GM12 bolt to a D60 so I had a similar problem. The original U-bolts are square to go over the springs with a plate on the bottom. After 40+ years, all that dirt piled up in the 4 pockets on each plate has most likely ruined the U-bolts. Time to upgrade.

I went, and also recommend, round type or normal U-bolts and fitted a flat plate on top of spring pack. I used off the shelf U-bolts from AutoZone and the top plates from a Jeep Cherokee in the JY. Easy peazy. You may have to find factory U-bolts due to the 4 inch tubes. And the top plate from the same donor. I was looking at dead Fords in the JY went I spotted the Cherokee.