The factory jetting recommendations are generally a bit rich. Looking a the Perf. RPM kit instructions on Summit, 100hp looks like 59N/59F. This will likely be rich.
The old powershot plates called for 47N/53F, I think I reversed them to 53N/47F and got close.
I was a overly conservative with mine and went a step colder plug as well pulling more timing.
Faster, Faster until the thrill of speed overcomes the fear of death...
71 Swinger - slowly collecting dust/parts 66 Belv. II - just a streetcar 88 Mustang - turbo LS beater