Okay so I felt like figuring out engine speeds.
According to this site http://mkiv.supras.org.nz/specs.htm the tires are size 255/45/17 which would make them 26" tall, and the available tranys are the 6 speed with either a 1.312 or 1.205 4th gear, the 5 speed is a 1.0 4th, and the auto is a .705.
Final drive on the N/A 5speed and auto is 4.08, the 6speed is 3.79
For an N/A MKIV Supra export
with the 6 speed its either 4473 RPMs or 4108 RPMs
with the 5 speed 3693 RPMs
with the auto 2604 RPMS
Hope this helps, only wasted 5 minutes fucking with that.
edit: I learned a few things about a Supra today.
edit2: yes thats for 70 mph