I just bought an 83 150 automatic. Pretty sure it has the 318 even though the previous owner told me he swapped in a 360. The tranny will not go into reverse and I cannot find neutral. I was told the torque converter is the reason but I don't see how that could cause it, the linkage is also messed up. It will idle fine but theres a spot right around 2000 rpm that it stumbles and tries to die like its loading up. The truck will also backfire a little bit when you let off the gas if you get on it, but that might be from the lack of exhaust(dual pipes dump under the cab). She runs strong at high rpms and sounds healthy so Im stumped. Also is there an easy way tell which automatic it has? Any help appreciated.

 

3 speed auto? most likely an A-727 torqueflight.

As far as which engine you've got, look at the driver's side of the block, toward the back, under the head. It'll say plain as day 318 or 360. My uncle's van was supposed to have a 318 in it (he thought) but it really had a 360. My buddy's 73 power wagon was supposed to have the 360 but some dingleberry put a 318 in it.