Little 20R is a trooper! Can't hardly kill it. Make sure all your coolant lines are in good shape though, overheating the R series is the easiest way to find out the limitations. I drove my '83 about 3 miles with NO water in the system. After blowing the hose I was curious what it could take. The last 1/4 was the final nail in the coffin. I'm sure you won't go this far, but the stock internals are good for 7000RPM all day long, but 7500 is a short fuse. That's info for that missed shift.
