First swap, what should I expect?

Got offered a free engine from a 75 dodge d200 custom by a buddy of mine looking to clear some space. It's got a 360 but I have no idea what kind of tranny is in it. It's got a clutch but also has a column shifter? Real oddball. Hoping for tips and insight. Looking to squeeze it into a 70 valiant.

Most likely you won't want the three speed transmission, I wouldn't. You will need a 360 car oil pan and pick up, a pair of car 340/360 motor mounts or modify a 318 drivers side and a set of car manifolds or headers. If you're running an auto a B&M 360 neutral balance flex plate is the simplest. You may need a transmission too if you're running a /6 currently.

Keep all the truck specific parts off the 360, someone will want it.