Motor and Trans 70 C10

[NewGuy70]

Hello all,
First time post here, I purchased a 1970 C10 long bed which has the 292 inline 6 in it. I purchased it without a motor and trans because I planned on putting a 350 in it. With that being said the guy I bought it from said it had 3 on the tree but inside the truck it appears to have 4 on the floor. Am I being a total new guy here or does that sound about right? I am also looking for a budget build to find a 350 what would you all recommend I don't want to spend 3500 on a crate 350 also a decent transmission. I want her to sound good and be mechanically sound don't need to turn under 10 sec 1/4 miles or go 120 MPH, just looking for a nice classic to drive around town and to and from work. Any other suggestions as far as the body or paint or any tips and tricks would be greatly appreciated. This is the first truck I am going to restore, I have some friends that do restoration helping me out so we will see how it goes.