if you get it back in, in the ballpark, you can leave the hold down loose while you rotate the dizzy with someone cranking the motor. when you get close it should fire. be careful and all that.
otherwise, go to TDC on compression stroke and restab it.
ive been shocked before touching a spark plug wire while the car was running. you can also try puttin in the distributor when the timing mark is at about 10* or so. make sure the rotor is pointing towards cyl #1 on the cap. if it doesnt start, take the distributor out and turn the motor over once setting it at about 10* again and that should do it.
Pull the number one plug. Rotate the engine by hand (ratchet/socket on balancer bolt) until you start to feel air come out of the plug hole. Now look at the balancer/pointer and keep rotating the engine until the pointer is lined up with 10-12 before tdc on the balancer. Drop your distributor in with module (the plug) facing about halfway between the t'stat housing and a/c compressor AND so the rotor is pointing as closely to the #1 spark plug wire on the cap as you can. It's easiest if you mark the distributor housing where the #1 plug wire on the cap 'hits' it. You may have to use an extension/socket to slightly rotate the oil pump shaft to get it to line up where you want it to. This will position the distributor so that it's trying to fire the #1 plug at 12 degrees btdc - should be close enough to fire. Then put a timing light on it, pull the spout and set it - preferably after it's warm.