Thank you so much for the reply. I really messed this question. I do understand the fluid drive better than you would be able to gather based on the way my question was written so i will try to clarify. Right now i have a 3 speed manual, column shift set up. There is definitely no fluid drive unit. So i was given a fluid drive unit that i have included the photos. The fluid drive unit already came with a 3 speed attached so now i have two 3 speed transmissions to choose from but only one fluid drive unit. If i remove the standard flywheel and bell housing it looks like the fluid drive unit will bolt right on to the back of the engine. The fluid drive also came with two different cast bottom covers (also in photos) They are different at the front face. One is flush and the other has a bump foreword ledge (towards the engine side)(see photos). Also, both covers have two holes that i am pointing at in the photos that do not line up with anything on the fluid drive. So it gave me some hesitation that there must be more than one version of the fluid drive that would bolt on. A very similar version of this engine was used in many cars so it is not exactly definitive that just because it bolts on that it really belongs in my truck. So that is really the question. Did the half ton trucks come with fluid drive option? and if they did, which model of fluid drive. Were the truck fluid drive units bigger? stronger? or exactly the same as cars. Now i know that i could probably adapt a VW motor and transmission to my truck but that is not my interest. I am also not really interested in bolting on a bunch of car parts either. So anybody has any knowledge of original configurations i would love to hear from you on this topic. Someone has already mentioned that the carb was different because it has a "dash pot". (would love more info on this) The fluid drive unit is longer than the standard bell housing so the transmission mounts further back. My fluid drive unit came with longer column shift linkage so i am good with this part. I am wondering if the speedometer cable & brake cable will be long enough or are these different part numbers. I will have to shorten the drive shaft too. I tried to make this question more clear by excessive ramblings. (LOL) Sorry. And thx for reading.