how do you now how much timing should you put to the motor

I have a 454 with etreme marine cam by comp cam 278du 565 lift 10.2:1 850 king demon should i just time by vaccum and how do you know how much mechnical advance thanks

I have a 454 with etreme marine cam by comp cam 278du 565 lift 10.2:1 850 king demon should i just time by vaccum and how do you know how much mechnical advance thanks
34-36 degrees total all in by 2200 rpm's. Some will say lock it out but others will differ....
396

Only put in the amount that gives the engine the highest RPM...no need to run 38 degrees if 34 gives the same max RPM.
Start out a 32 and go up till no gain in RPM at WOT...done deal.