I didn't know where to put this

I just bought this today for 1300. He said it has a transmission problem.. Its an 87 Mazda with a 96 318 Dodge Ram complete computer and complete harness including the stock F.I. and transmission. Of course like all conversions it needs things but the owner knew absolutely nothing as he only had it a month. He said that it shifts up than down and up again whereas he believes it is a 3 speed, yet as I looked under the truck, the trans seemed way to long to be anything other than a 518 4 speed, yet I can be wrong as well and I'll know when I put it on a lift. I think he thought it was shifting erratically although the power was there from the get-go and shifted pretty damn well to me... And it's stuffed in that compartment pretty tight. What do you think?