I drove a 4 cyl Ranger with a First Gen turbo. It spools at about 6000rpm, and then she gets SQUIRRLLLEY. Oo.
It launched the head right off, then they rebuilt with studs, etc. 22psi. Then it blew also. 280 HP on the rollers.
I would definateley try one on the 4. 0--properly wastegated, of course.
Not much room in there.