Hey Dan,
Have you tried the WIX 33405? It is a 1x14 thread and including the petcock is just over 7" long. I use it on some equipment and thought it may work. Here is a list of a other 1x14 filters that cross with it but are different lengths etc.
Caterpillar Primary Filter/Water Separator 175-2949 (threads 1-14 UNS-2B )
Fleetguard FS19683
Donaldson P551743
Baldwin BF1268
Wix 33005
Luber-Finer LFF8030
ACDelco TP1002
Caterpillar Secondary Filter 1R-0749 (2 Microns) (threads 1-14 UNS-2B )
Fleetguard FF5319
Donaldson P551311
Baldwin BF7587 (BF614, Standard Version, BF7633, Short Version)
Wix 33674
Luber-Finer LFF2749 (High efficiency version of LFF5823B)
ACDelco TP1322
Fram P8335
Purolator F75185
Hastings FF1056 (FF1007, Standard Version FF1079, Short Version))
Caterpillar Filter 1R-0750 (2 micron) (threads 1-14 UNS-2B )
Fleetguard FF5320
Donaldson P551313
Baldwin BF7633 (BF7587, Long Version)
Wix 33528
Luber-Finer LFF3347
ACDelco TP1326
Fram P8334
Purolator F65213
Hastings FF1079 (FF1056, Long Version)