It's actually not that difficult to narrow a Jag. Jerry "Ma_n_Pa T"
(profile here) narrowed his a while back and wrote about it on one of the T forums. Also, a guy did a
nice write-up on narrowing a Jag for a Mustang. Just about any drive-line shop (i.e. Inland Truck Parts, Denny's Driveshaft, etc.) could do it as well, but they might be a little spendy. There also after-market shorter parts out there (i.e. Heidt's, CWI) but they are
definitely spendy.