Check this thread out John:
http://www.onlycubcadets.net/forum/s...highlight=1863
I believe, from pics I've seen, some of the 1641 models use the same hydro as the 1863. I deduce this from the manual hydro release valve in the drive shaft cover.
The 1864 does not have the manual hydro release but, has power steering.
The Owners Manual that came with the 1863 I have states the hydrostatic relief valve only comes on an 1861, but there is one on the 1863.
I suspect some of the variances in builds had a lot to do with part availability during manufacturing.
PeterJ
__________________
1863 48" deck, 3pt
1864 x 2, 54" deck, power bagger, 48” deck
1811 44" deck 1210 44"deck
IH trip plow
QA42-A, 451 x 2, 551
42" Earthcavator
Driveway Drag
USAF
Shepherd's Chapel