How to Install a New Distributor

Another Method
This method should be used if the engine has been cranked while the distributor is out, or if the engine is fresh and you don't know where the No. 1 piston is in relation to TDC.
Another Method This method should be used if the engine has been cranked while the distri
The idea is to put the No. 1 piston at TDC, install the distributor slightly advanced (like 15 degrees), and adjust the timing with the engine running. Or you can put the piston at 15 degrees BTDC on the compression stroke and point the rotor right at the No. 1 position on the cap. We prefer the second method provided we can see the timing pointer and it is indexed with numbers; some of them aren't. If you just have a big blob on the balancer that is marked with a big TDC, you get to use the first method.
The idea is to put the No. 1 piston at TDC, install the distributor slightly advanced (lik
To be sure that the piston is on TDC on the compression stroke, you can put your thumb over the spark plug hole and crank the engine. When the mark is on or near TDC on the balancer and compressed air is pushing on your thumb, you are there.
To be sure that the piston is on TDC on the compression stroke, you can put your thumb ove

But what if you don't have a battery and you can't crank the engine? You can also pop a valve cover and watch the valves. If you are at or near TDC on the compression stroke, both No. 1 rocker arms will be slightly loose and the valves will be seated. It's trying to make compression, after all.
But what if you don't have a battery and you can't crank the engine? You can also pop a va
When you are sure that you are on the compression stroke, line up the timing pointer at 15 degrees BTDC or whatever your engine calls for (you can't ping at idle so we usually set 15 as a baseline for all engines). Drop the housing into the block, making sure that the vacuum advance or wiring harnesses don't bump into anything when you twist the housing so you can tweak the timing later. Once the housing is in, mark where the rotor is pointing on the side of the housing.
When you are sure that you are on the compression stroke, line up the timing pointer at 15
Now that you know where the rotor is pointing, you can mark the No. 1 terminal on the cap so you know where to start the spark plug wire routing.
Now that you know where the rotor is pointing, you can mark the No. 1 terminal on the cap

With the rotor facing the No. 1 terminal and the distributor locked down with the pointer lined up with your base timing (15 degrees), you should be able to go through the firing order and run the wires. If everything is doing its job, the engine will fire right up and idle at 15 degrees BTDC. Check it with a timing light. END
With the rotor facing the No. 1 terminal and the distributor locked down with the pointer