440 timing gears

Bear in mind that MOST engines when lined up that way --the way the books tell you-- the engine IS NOT "ready to fire" on no1. It is instead on the no6 compression stroke

So after you install your new cam SPROCKETS and properly line them up, and put the engine together, ROTATE the engine one full turn before dropping the distributor in on no1

Two ways to tell for sure that you are on the no1 compression stroke:

If the valve covers are off, look at the no1 valves, If the no1 valves are both CLOSED you are on the proper crank rotation, the compression stroke. If they are both open, rotate the crank one turn.

If the valve covers are on the engine, pull the no 1 plug, stick your finger in the hole, and bump the engine on the starter. You might have to "go around" a couple of times the first time you learn this. When you feel compression push your finger out, STOP and look for the timing marks, which should be "on their way up." Now be more careful, bump the engine, or wrench it over until the marks are lined up NOT on TDC, but rather BEFORE TDC exactly where you "want" the timing to be, example, 12* BTDC.

Now drop the dist in with the rotor pointing to the no1 plug tower. An easy way to do this is mark or scribe the top rim of the distributor housing so you don't have to argue with the cap.

On a B/ RB engine, "retard" the dist. is moving the housing CCW. So retard the timing a bit, and slowly bring it back advanced, CW

If you have "points" ignition, advance until the points JUST open, use a meter or light to see this.

If you have breakerless, line the reluctor tip up with the center of the pickup coil.

This method should be close enough that the engine will start and run, timing wise, with no fuss.