Found a bunch of different info on the item here is some of the stuff I found:
Amazon.com has a couple different options:
http://www.amazon.com/BCA-National-9...tive&carId=001
http://www.amazon.com/gp/part-finder...0741&carId=001
RockAuto.com seems to think it is a "8792S" but I am not sure about that one:
2001 ISUZU VEHICROSS 3.5L 3475cc V6 FI (X) [6VE1] : Transmission-Automatic : Shift Shaft Seal Price Core Total
BCA/NATIONAL Part # 8792S {Oil Seal / Nitrile / Shaft Size=0.5" Housing Bore=0.751" Outer Diameter=0.756" Width=0.192"}
GMC 4L30-E 4 Spd. Automatic Transmission $3.58 @ Rock Auto
photo of item:
http://info.rockauto.com/BCA/Detail2...ages/Seals.jpg
Item listed at Amazon, but amazon says it does not fit the vx:
http://www.amazon.com/National-Oil-S...7852132&sr=1-4
http://www.amazon.com/TIMKEN-8792S-T...7852132&sr=1-2
Anyways, hope that helps.