i’ve got a 1994 4.0 v6 5 speed splash single cab, transmission went out and i don’t want to spend 1800 on a reman, i can find them all day for 800 on marketplace, ive found a 2003 with a 4.0 v6 5 speed someone is parting out, will i have any issues fitting the 03 trans in the 94 or are they the same since they have the same motor, also how much trans fluid and what type does everyone recommend.

 

At how many miles did your '94's transmission fail?
1994 still had vacuum modulators. The '03 is all electrically controlled.
1994 had the 60 wire brain (EEC-IV / OBD I).
After that the 104 wire set-up was used (EEC-V / OBD II). Also, two more solenoids were added.
I don't think they swap.
Maybe have your own unit rebuilt?

Both take ~11 qt. of Mercon V. Mercon V was back specced to older Mercon applications.
Many use various multi-vehicle ATF without issue.
Since Mercon V is still easy to find, I use that. I bought some at a Walmart recently.
It can sell out as they don't order much...go online if that occurs.

 

the previous owner said truck has 132k, failed about a month after purchase. not exactly sure what failed but i can’t find any rebuild kits. there was a bunch of metal in the pan. can’t find any 94 4.0 v6 5 speeds on marketplace.

 

"there was a bunch of metal in the pan." <<That's bad

I've heard the terms "hard rebuild" (total replacement hardware-drums, clutch packs) vs a "soft rebuild" (just friction materials).
Get a hard rebuild...even if transportation is involved.