[jeepjunky]

1980 CJ-7: Are all the frame rails boxed in? Mine are...is this stock or did someone do me a favor?
When changing to a YJ spring you only have to change the front because the back is allready 2.5 in? also my front end back hangers are 2 15/16 in in size no mods are needed correct to this part. Finally whats the reason for changing to wider front spring?
My Jeep is fairly stock mostly driven on pavment (dayly driver with better mpg than my '99 Grand Cherokee) put dose go wheeling. 30x9.5 now liking to go to 31x10.5? not sure though??? It needs a more aggressive look but still safe and fun to drive!

 

[Raduckal]

AMC started boxing the frame in 1976.
31x10.5 will work fine. I run 32x11.50 on my stock 81 with minimal rubbing.

 

[Guest]

When changing to YJ springs in the front, the spring is also about 1" longer. When I did my SOA, I removed the old front spring hanger...drilled out the big rivet, and installed a stock rear hanger 1" forward using the hole the rivit had been in....works great....and the new hanger is stronger than the old original one.....

You might also have to lengthen the front ds....if you do any lift, it will for sure need to be lengthened