1963 thunderbird 390 engine replacement?

I would guess about 15, but that is just a guess.

To do one correctly as far as cleaning it up, painting, heads milled, and everything, you are looking at at least 40 hours or more typically a week maybe week and a half. That is considering hooking up all the a/c lines and getting everything ready to crank and drive.

He said engine replacement and mentioned nothing about rebuilding the engine.