Hi, Peter

does not your oscillator run or does not your program work as expected ??? Here is THE big question ...

80 Mhz looks to be "reachable" ( with careful design ... ) with Pics but, as PBP "timed " commands are not available for more than 64Mhz clocking, some commands in your program can't work properly ... ( assembler Ghost in sight !!! )

sooo, to me, it's no use to go on the " overclocking way " ... without using some assembler.

Sorry ... Even I do love Hondas ( mine is a 2020 Civic 4D 1.5L CVT ... and I Have Driven only Hondas for ... 32 Years ! )

Alain