Distibutor Replacement

I have been doing some engine work on my 66 coupe with a 302.  In doig this work I was taking out the distributor so that i could clean up all the intake better.  However, before i took the distributor out, i forgot (well distracted by the better half) to mark the position of the rotor.  Now, i have no idea what position the rotor should be in when i replace it.  How is the best easiest way to fix this little problem?  Any help would be greatly appreciated

Thanks,  

Ohhh Bob Bob Bob ,,,, how many times have the rest of us done the same thing,,,arghhh painful isnt it. The only way to do this right is to turn over the engine to no 1 cylinder (front passenger side cylinder closest to the radiator) TDC ,,,top dead center. I never rely on the timing marks because they are frequently bad on these old cars as the balancers tend to move. Make sure you have Firing top dead center by checking one of two things. First the intake valve will open then close just before TDC and there will be compression in the cylinder. Some people use their thumb over the spark plug hole to assure its the compression stroke but watching the valves is foolproof. If there is no compression then you're on the overlap stroke and you need to go around again(remember a four stroke fires on every other TDC). Once you confirm you have TDC on no 1 cylinder then note where your number 1 plug wire is on the distributor cap and set your rotor approximataly on the firing post. This will get you close enough to get the engine fired and then use a timing light to see where you are. Ignition timing should always be set advanced as much as the car will tolerate without pinging,,, or some mild pinging that is short lived. This is the setting that will give you the best power and economy. Usually this will result in about 8 to 12 degrees of initial advance, but as I say remain aware that marks on the balancer are prone to movement over the years.  

Thanks for the info and that is what i figured i would have to do, just hoping there was an easier way.  Yeah its a bad mistake, but must move on.  

I think i have a good idea where the rotor was?  So i might try it there,  but if i do and I am way off like completely the wrong side of the distibutor, what will happen when i try to start it?  Anything bad or will it just not start?

thanks again  

Probably nothing bad ,,,, backfiring and general upset.  If you can get it close you can get it started.