I set my timing to 12* at idle w/out vacuum line connected. My car now has a hesitation that it didn't have when I had it set at 12* w/ the vacuum line. This doesn't make any sense to me. The distributer is a NAPA rebuild for a 69 stang 351, so I think the springs should be close right? What does everyone else w/ 351 strokers run for initial timing, and should the total kick in when it is in park at 3500RPM, or does there need to be a load? Sorry about all of the questions, I am just scared that I will advance it too much and not hear the pinging w/ my dumped 2 chamber flows.