I have just put a four speed in my 1000, now because it was a factory 3 on the tree I think the diff ratios must be pretty short as in 3.9's or something casue the four speed gave me no love when it comes to easy highway cruizing, I am still reving at the same RPM as with the 3 speed. My question is, what diff can I put in my 1000. I dont care about making new mounts or mucking around changing handbrake arrangements as long as the track is the same width. I can get a 120y 4 speed wagon diff, will this fit, and what will the ratios be?? Any advice on what will be a nice easy change over and help drop RPMs would be greatly appreciated.