I'm finishing up a 84.5 by 89 b-series and I'm shooting for at least 250hp. I've read a lot of positive feedback on RaceGas which lets me raise the octane level of pump gas but need to understand what to look for when tuning timing advance to take advantage of the higher octane. Do I basically read the plugs while advancing or is there another method?

 

dyno is your best friend here

 

Exactly - I will be getting the car tuned on a dyno. My question is for personal knowledge as eventually, I want to be able to tune my own car/

 

At the dyno, you'll be looking for MBT. Once you get it, you'll be fine. Check for the tuning guides on this forum! TL;DR: add timing by 1* or 2* until the curve peaks, then remove 1 or 2 degree to be safe.