If I was you I would not mess around with cam timing, only ignition timing. I would advance 2-3° over stock and leave that be. Advancing the ignition timing just moves the torque curve lower, it doesn't make any extra power. I would also change every single fluid in that vehicle and every other wear part. You are only what, 800 into it after registration fees?
I fear cyl 2 and 3 are way worn. You should run Restore engine lubricant and restorer, link here:
https://www.summitracing.com/parts/r...saAmeIEALw_wcB
Project farm on YouTube had great results with it.