351w

Unfortunately the engine in there now is a 4 cyl. And the mustang is the 3.8, so neither would be a drop in fit. I got the ranger for basically free, and it gets driven daily with the current engine and 5 speed manual transmission. But has 240,000 miles on it, so eventually it is going to give up. I also have a 4 cylinder perkins diesel that I picked up for $100 that was out of an '84 ranger. That may go into a little rock crawler project. But that's another day.
That iron head Ford 2300 in that ranger is like their version on the slant 6 they are pretty indestructable. 240K it may just live to over 300k as.long as you dont run it out of oil. If your waiting till it pops to drop in that 351C , you may be waiting awhile LOL