500hp carb, initial timing 10 and total timing 3000 rpm and set at 34 is this all correct.

that should be fine.

I run 12 and 36. But 10 and 34 would be a save starting point.

Don,t forget to ground the timing wire.

what wire i never did that before when i timed these engines.

HP 500 carb You must ground the timing wire to put the spark knock module in stabil mode. should be a purple wire with yellow tracer, rubber plug in the end. rear of intake manifold. See mercury manual under M B T adjust tune, Means Best Timing.

If tis a TB V you need to put it in timing mode as stated. If its TB IV, you don't need to do anything.