71 LA 340 timings moved!! how?? looking for help

If someone mention this already im sorry didn't see it. Possibly to light on the advance springs? If its acting up during rev's there's a chance the springs are not opening in a control manner. It could be bouncing around as its opening. Sometimes people the lightest springs they can find in order to get the motor to rev up quicker sure the advance cams open more aggressively but like I said it can cause the advance cams to bounce around causing issues.