OK, this is odd. OP can you verify your specs?
I'm not finding that '87 - 4.0 - Manual combo anywhere.
Might want to just measure the collapsed length of the shaft you have and compare it to this:
XJ 87/88 2.5 Automatic 27.950 53003912
XJ 89/93 2.5 Automatic 27.970 53005540
XJ 89/01 2.5 Manual 25.310 53005541
XJ 89/01 4.0 Automatic 30.660 53005542
XJ 89/01 4.0 Manual 29.250 53005543
XJ 89/00 4.0 Manual 27.080 Export 53005544
XJ 89/00 4.0 Automatic 28.620 Export 53005545
XJ 87/88 4.0 Automatic Export 53005260 *
XJ 95/01 Diesel 27.640 Export 52098208
ZJ 1993 4.0 Automatic 30.530 52098341
ZJ 93/95 5.2 Automatic 32.870 w/o CV 53008427
ZJ 94/95 5.2 A500 30.625 w/o CV 52087805
ZJ 94/95 4.0 A500 w/o CV 52098790
ZJ 93/96 4.0 Manual 52098344
ZJ 93/96 4.0, 5.2 31.875 w/ 231, 242 52087805
ZJ 93/95 4.0 Manual 30.000 w/231 52088090
ZJ 93/96 5.2 33.000 w/ 231 53008427
ZJ 96/98 5.2, 5.9 31.250 w/ 249 & Model 30 52098379
ZJ 1996 5.2 Automatic 32.875 w/ 249 & Model 30 52098501
ZJ 96/98 4.0 33.000 w/ 242 52098707
ZJ 96/97 4.0 Automatic 31.250 52098850
ZJ 1996 5.2 Automatic 30.750 w/ 249 & Model 30 52099246
ZJ 96/98 4.0 33.500 w/ 249 52099260