I'm swapping in a 350 into my 305 TBI Camaro this weekend. I have an external mounted coil distributor. How do I make sure that I properly install the distributor in my new 350?

 

It's been described on the Tech forum a few times.

Bring the engine over to #1 at top dead center. With the spark plug out, turn the engine over slowly until the timing mark is approaching the tab, and air is being pushed out of the cylinder (hold your finger over the spark plug hole as you turn the engine over - when you feel pressure, you're on the compression stroke of cylinder #1).

Put the distributor in the hole, with the rotor turned about 30 degrees counterclockwise from the #1 position (pointing at the #1 spark plug wire if the cap was on the distributor - which it won't be, because you can't do this with the cap on). Drop the distributor down into the intake manifold hole, and as the distributor gear engages the cam gear, it will turn clockwise. If it doesn't drop all the way down, the oil pump drive shaft isn't quite lined up - you can bump the engine over until it drops in, or try to align the oil pump shaft so it will drop down.

After you get the engine started, you will have to do the final timing setting with a timing light.