gjberche,

Here is a picture that shows the setup as I remember it. The bolt that is pictured in the elongated slot is how you adjust all timing.

The screw is difficult to access because it was never intended to be accessed on the rig...it isn't a adjustment point, only a assembly point.

http://chevy.tocmp.com/1948_51truckshop/51ctsm0619.htm

Stuart