.. Those old Willys were made right here at Willys/Overland plant... still a lot of them around here... as are Jeep Wranglers made here and until last August, the Jeep Liberty (sometimes still called a 'Cherokee' in foreign countries that don't like the word 'Liberty') and, up until a year or so ago, the Dodge Nitro version of it...
.. Here's a slick, handy online calculator for RPM vs tire size vs rear ratio vs tranny gears vs MPH (click 'clear right' button before doing anything). Gives a great spreadsheet of info:
.. One of my current projects is a SBC 405", MoTown 220 cc alum. heads, Summit #1105 224/234 hyd. flat cam... it's on its 3rd or 4th set of heads and intakes and hasn't even run yet... LOL! . Another is Ford 351"M/400 block 2bbl. getting 400 crank, KB domed pistons, 214/224 cam, and 4bbl. carb. for an F150..