JEFF, if you want to run in the 70s.
Need to change the crank timing, the stock timing is about 205, open the timing up to 215. closes at 65 ATDC.
Cut the ex. to 30 degree blown down.
Get OPS pipe and run it at 7 3/4 with H-7 prop with 3.6 pitch, it will run in the 70s all day
Norris