Well, in an ideal world you should be able to fire it up, with everything set( timing,mixture for the carb etc.) then raise the idle speed. You should be able to get your base timing pretty close by hooking up a timing light, and with the key in the run position,and the crank turned to your desired timing position,rotate the distributor until the light flashes. You may have to do this a coupla times but then you can fire the engine knowing that you should be within a couple of degree's. When you do fire the engine, immediately raise the rpm's and fine tune the timing by ear. Of course you can't set it completely correct at high idle, but you should be awfully close. And don't forget to keep an eye on the coolant and oil pressure gauges.