360 timing

i was under the impression that if i didn't limit the total timing that i would damage my engine. That if i didnt get my timing worked out, i wouldnt be able to tune it properly.
I was refering to ebay listing - 85 negatives in the last 12 months.
Unfortunately there will not be room for the big cap distributor in my car. I was loving the price!
I am really considering the mre-90430 with the orange ecu. but i will have to save up a bit. I wish mancini took paypal.
And back to installing a new vac advance. if i go back to 12* initial i am going to have vacuum in the sparkport at idle.