I am looking to swap a 231 from a 2001 XJ into my wife's 98 5.9 that currently has a 249 with a VC that's going out. Do I need to swap the output shafts? The 231 case looks like it has a little longer output shaft than the 249. Or could this possibly be a good time to throw on a small spacer lift and I wouldn't have to mess with swapping outputs? Thanks.