1968 340 timing

Cool, I was playing around with it last night after work, setting total then hooked up vacuum,came in at right around 50. I had heard engine damage may occur, if over 36 total timing etc,but it was running god at Idle, I will next get it going down the road under load and go from there. My goal is to get it to **** and git as best as possible,and even more I want passengers to hold on to the dash and beg to be let out at the next corner;)