A body 8&3/4 housing shortened by Moser to 52 & 1/8" (1/4" per side). OE 8&3/4 A body axles. open 742 pig. In mockup right now. How do I determine the exact amt to chopsaw off of each axle? (yes they'll be enough splines left, at least 1"). On the pass side I'm seein 5/16" from the backside of the bearing flange assy to the thick aftermarket white foam gasket. it is way thicker than the OE ones (which were compressed of course when removed but...) & I'm sure these will compress, not sure how far. Ain't got to pass side yet. I'm thinking I want the axle to be short enough to just butt against the thingie in the center of the pig then do the pass axle. it'd be like slicing a loaf of freshly baked bread, I cant slice it thin like a deli meat slicer can so I'm thinking with the little bit I need to remove I have one shot to cut it dead on. What's my next (correct!) move? Thanks guys!

Dr Diff could likely provide the best advice.

That said, measure twice and cut once.

I had to cut around 1-inch off an axle to mount in a Dana Rear around 12-years ago (as with yours, plenty of spline as they were aftermarket axles).

I had Factory Dimensions to work with, less the amount that the housing was narrowed. You could be conservative and cut off the 1/4-inch and grind the end with a disk grinder (cooling periodically so as not to adversely affect the heat treatment) to get it to finished length, or just go for it and cut the 5/16.

Of course, it is easier to cut length off than glue it back on if you took too much off.

Perhaps you can measure the needed length with a dowel rod to transfer the length for a more accurate dimension?

Granted, you need the length to be correct so that the axle ends don't bind in the center, so a little short is better than a little too long. Thinking, does it have a Button (disc) in the center of the differential to keep the axle ends apart (thing'ie thing you were talking about?

Of course, easier to cut too much off than glue it back on if you went too far and Absolute worst case you would need to buy new axles, if you cut them too short.

yes it has the button in the center (5:57 open in a 742 case with welded spiders). I will email the Doc. I do have the "leadmine products" flat plate that bolts on the open housing with pig out then you tape out to the end & add on the standout to get the axle length you need but with those super thick foam gaskets that I purchased & my natural tendency toward OCD I started worrying & figured I better inquire & I will see what the leadmine gauge tells me (as you noted I can only cut once on this deal) (& call Doc)

Are you converting to / using Green Bearings? Those really helped when I did mine.

http://www.doctordiff.com/blog/tech-info/why-green-bearings/

no greens on this deal

OK, housing is 52 1/8", add 1/8" to each side for the backing plate and gaskets so you wind up with 52 3/8". The thrust block in the center is 1 1/2" so subtract that and you have 50 7/8" divide that by two and each axle shaft needs to be 25 7/16" from the tip to the inside of the bearing retainer.

John is the man (as always!)

Alright, I pulled the bearing race in so it covered the bearing rollers completely (alot of freeplay there) & then measured from the inner flat face of the bearing retainer out to the end of the axle & got 25 & 11/16". John gave me 25 & 7/16" which is exactly the 1/4" difference the same as the amt the housing was shortened on each end! If those thick white foam gaskets from Evilbay cause a clearance problem I'll just use some gasket cement and or make a super thin gasket from some stock. Thanks guys and especially you John.