I hate to break it to you, but if you need "advice" on turbocharging or supercharging something, you need to find a different project. Pretty much anything you do for performance on old Rangers is going to require a lot of fabrication and tuning knowledge. There is essentially NOTHING in the way of a kit out there. You may be able to find an old Explorer Express or Vortech supercharger kit for a 4.0 and modify it to work, but that is still going to require a lot of tuning and fabrication. And to be honest, even if you do manage to get a turbo/supercharger on there and functioning, it isn't going to be all that powerful. You won't be able to run enough boost to make it fun without pulling the engine and putting some forged pistons into it. I had a 4.0 OHV with a roots supercharger making 5-6 psi, and it just wasn't what I wanted. A 5.0 swap would have been faster, easier, and much more powerful. Either do a 5.0 swap, go with a 2.3 turbocoupe or 3.8 supercoupe engine if you have to have forced induction, or find a different hotrod.
Just my $0.02.
