I have just replaced the engine with a brand new 12a, I have a brand new racing beat conversion holly carb and intake. All emmision removed. Car runs but idles very rough and starts hard when warm. I think timing is incorrect. On distributor do both vacum pots have to hokked up?on main pulley is the leading mark the first on the pully? I would like to change this distributor out compleatly but I heard thats expensive. This timming is giving me problems

 

I like to hook up the vacuum advance diaphragms. You can tee them into one line and connect it to the second nipple from the front of the carb on the left side of the car. Leading timing mark is the closest to the left side of the car. Trailing is the one closer to the right side of the car. Turning the distributor counterclockwise retards timing, clockwise advances timing. Generally less advance = better starting and better low end power. More advance = harder starting, better top end and more chance of detonation (not good).

 

thanks great help