Initial timing set @ 30*. Engine seems happy?

Isn't the harmonic balancer keyed to ensure proper index? The balancer on the engine has the timing marks stamped in it @ 2* intervals. I'll double check anyway, but I didn't think it could go on wrong.

I don't have a vacuum gauge. Could I use my timing light to advance until the RPM is the highest, then retard a little? Or do I need a vac gauge To find it proper?

Thanks for all the help so far! :)