72 360 first start question

So, I decided to go back to square one. Originally I had found TDC by finding the highest point of the #1 on the compression stroke. and then reversing it until it was the highest pint again. I did not use a piston stop to do this. I used a screwdriver in the piston hole and thought that i had found the two highest points which re vealed the TDC to be 10 deg. after TDC. So this morning I made a piston stop and did it all again and realized that my factory timing mark was actually correct. Crazy how far off the screwdriver technique could actually be. So that's good news , actual TDC lines up with the factory dampner mark. Unfortunately, I set the initial timing to 12 degrees BTDC and it acted exactly the same as it had before. I set it to 15 BTDC and same thing. I set it to zero and same thing. One thing I noticed is that no matter the initial timing setting. I fire it up and it revs pretty hard before settling down. I still can't get it to idle below 35 deg. advance with the throttle pretty signifigantly advanced. It will run there all day and sounds good, but if i lower the throttle or retard timing it still dies. I'm starting to lean towards vaccum leak or throwing a match in it. any thoughts?