Where are you timing tab?

I recently bought a '65 Barracuda that someone put a '70-'74 318 into. I put a new Edelbrock carb on, gave it a full tune up, adjusted mixture & idle with a vacuum gauge. Now I want to check & maybe tweak the timing however there is no timing tab anywhere on the motor. Does anyone have any ideas? There is a line on the balancer but nothing to line it up against. Should I try to time it by ear or with vacuum gauge? Can I add a timing tab? I can't seem to find any aftermarket ones. Any advice would help. Thanks in advance for help.