nothing wrong with the 77 440. Not going to make a ton of power without pistons and a decent cam.but it will run on any unleaded swill you can pump in.
the 68 383 is a great motor, makes good power and likes RPMs, needs Premium fuel only, unless the comp is lowered...

I would go on conditon of the donor motor combined with the amount of time and money you want to spend on freshing..