Please help diff build/ ratio change

[S body 14a]

Hi guys,*
I recently purchased a non abs skyline 4.1 diff that I wanted to swap into my s14 3.7 abs cased diff. ( just to change the ratio so pinion and crown)
I need to keep abs case as its for the speedo in my s15....

I was told that everthing would be a straight swap. However after stripping down both diffs today it's clear that it's not the case. My problem is the pinion from the skyline diff has a different shaft bearing and the shaft itself is slightly different!
so won't fit in the abs case?*
Also the crown off the skyline diff won't fit the s14 vsld as the bolts that hold the crown on are different thickness... I was tgen just going to fit the complete skyline internals to the abs casing, but again as the skyline pinion won't fit in the abs case I can't do that..*
I really need help as my car now has no diff in it..
do I need a abs skyline diff?*
I only want to change the ratio on the diff.

Any help would be greatly appreciated*
cheers kev

[Mike41288]

I got a place to do, for me, exactly what you are doing. So it can be done without extra parts. I think you have to put the skyline pinion onto the abs pinion shaft the the skyline diff with crown wheel in. My ABS sensor also had to be removed/broken to get the pinion shaft out but I'm not sure if that want due to it getting new bearings/seals or not. I'm just going by what I was told by the guy. I'm in no way a diff expert!

[S body 14a]

Both pinions are out of the diffs now. It was just resembling the diffs back together is the problem. I will see if there are any companies that will do it for me. At least I know I've got all the parts now.. if anyone else has any ideas or ways to assemble it I'm all ears. Cheers