Does it matter which direction the timer roller is installed on the camshaft in relation to the crankshaft?
Yes it matters, it's ether right on or 180 deg. off. 180 off=no run!
?? It will only go one way.
Sounds like he has one of the cam shafts that the hole goes all the way thru.
Mark'point is correct,but only if you're using an early cam that is drilled all the way through for the timing pin.
It can only go on one way on the later cam shafts, the body that slides on the cam has a slot that takes a pin into the hole in the cam and a cap that go's over that then the nut, same for the earlier cams but the hole for the pin go's through the cam so you can be 180 degrees out on fitting.
Hole is drilled all the way through. What's the best way to insure I install it correctly?
Turn the engine so that cylinder #1 is top dead center on compression stroke. Place the roller to point at terminal #1 on timer. Note, it might be slightly before or after #1 terminal, but closer to #1 than any other terminal. After it is installed adjust the rod so that the spark comes just after top dead center.
I should add spark comes just after top dead center with the spark lever all the way up.
On my 17 the roller can go on either way. Don't ask me how I know that.
Don't you run yours clockwise on even days and counterclockwise on odd days?