hey guys, Ive got a 620 ute diff laying around and was wondering how much work it is to put it in the sedan. Ive heard that they are pretty much bulletproof. Will it have to be narrowed?

The 620 ute diff is the right width it wont need shortening. You will need another tailshaft to fit to it & you will also have to redrill the axle as its 6 stud instead of 4 stud .
Cheers Andrew

This is interesting. So you say they are the right width. Does that mean its the same or close to the same width as a 1200 rear? I'm sure its heavier than a stock 1200 rearend, but is it too heavy?

they are a pretty heavy diff but I think it would be worth it, the axles are HUGE, pretty similar in size to 9 inch axles. I dont know which setup to go for. Are you using the scorpion diff andrew? How do you find that?

Yeah I was thinking about using a truck diff as well, but wasn't sure if it had been tried yet or not. The 71-73 620 truck uses an H190 (AL) rearend, which has an aluminum housing. Later 10/73+ models used the H190 (ML) rearend, it's a cast iron housing with larger pinion shaft bearings. The NISMO LSD for the ML rearend part# is 38420-41W00, and there is also a Detroit Locker assy available. Sounds like a good option if you can't find a 510 wagon or Roadster H190 w/4lug. Is it hard to get the 6 lug rearend changed to 4 lug? How much does that usually cost?

-Andy

Converting from 6 to 4 isn't too hard. Me and my dad did it for my shortened commodore diff. You need a metal lathe to do it neatly.

I machined up plugs for the bigger holes in the axle face, and then using a BIG MIG, I welded them in (plenty of weld penetration). I then used the lathe to machine the faces smooth.

I made a jig that is used to space the holes after the first one is drilled. It's essential that the first hole is drilled exactly on the PCD for the other studs. I machined a line exactly on the PCD to direct the drill tip. I then put the first stud in, and used my jig to direct me where to drill the next hole. I keep going until all 4 are drilled. You need to use exactly the right size drill, otherwise the studs won't hold tight in their new holes. Near enough isn't good enough for this job.

Chris