new engine and trans for a 69' C10

i was wondering how hard is it to put a 350-454 engine and auto trans in a 69' C10?

reason being is that there is a 69' C10 for sale near my uncle's house for $500 and is in good shape from what i'm told but it does not have a engine and trans.

Chevrolet trucks are probably about the easiest vehicle to swap engines with. If it had a manual trans or three on the tree you have to drill the rivets out of the old trans crossmember and relocate it. This is a real bear because the rivets are hardend steel, took us about a day on one we did. It was a long time ago so I do not remember all of the details but there is plenty of room under the hood for anything you want to drop down in there.