I had a '73 Sportster back in the day. Right side shift, ran great for me. (of course I rebuilt the top end twice) That was in my long haired "screw everything" days. I sure miss that bike, like every other one I've ever sold.
Timing specs? As I recall, you take the plug out of the left side of the crankcase and endure a bath of oil spray with timing light in hand and get the timing between the two marks you may or may not see through the fog spraying out of the open crankcase port. You can buy a clear plug to go in the port, but you can't see through it anyway with the oil slinging around in there.
Having said that, those old ironheads were a lot of fun to ride and were really simple and fun to work on. I'd buy a service manual if I were you.
