Just pondering the idea of a all aluminum 4.6 to put in my '77. It weighs less than a 302, and can get a lot of HP out of it. I have access to 1 with an AOD for $650. Of course I'll have to get a stand alone management system. But I was thinking of using Megasquirt as they have 1 already for it!!

Not sure it would really fit without a major amount of work. The 4.6 is a fairly wide engine. It's a tight fit with a smallblock Ford or Chevy in one.

A 4.6 is extremely wide. Creating a working oil pan & pickup should be interesting. The firewall, heater blower & master cylinder are gonna be in the way.

FYI, Pinto unibody does not have really stiff front frame rails. Cutting fenderwell out in the wrong way can greatly weaken the entire 'box' that stiffens up the whole thing. The shock towers and further forward wells provide stiffness to locate the frame rails further as far as movement under load. The front radiator support structure reinforces all that to make the 'box'. That allows for lighter thickness front frame rails that cannot stand alone by themselves unlike a true full frame car that can.

You CAN cut there if it is done intelligently but you'd best have some ideas as to load bearing and things like that.

Yeah just enough for headers. Plus welding in sub-frame connectors.