Not an "A" guy but since the bolt is in a cast boss it would be original. Hercules and others used similar to set end play in cam and accesssory drives.
Tim,
The direction of the helix cut(left or right) denotes which way it " loads " the
cam shaft. The Model A will load it back, the 32-48 Ford V/8 is also the same,
the 49-53 has an opposite helix and loads to the front, BUT has a thrust button
to stop the cam from screwing it self out the front cover. Even when doing a
49-53 I use a earlier gear set, works better.
Jay Steele, of Taylor Engines, is a sharp engine builder.
Dudley
Tim,
The direction of the helix cut(left or right) denotes which way it " loads " the
cam shaft. The Model A will load it back, the 32-48 Ford V/8 is also the same,
the 49-53 has an opposite helix and loads to the front, BUT has a thrust button
to stop the cam from screwing it self out the front cover. Even when doing a
49-53 I use a earlier gear set, works better.
Jay Steele, of Taylor Engines, is a sharp engine builder.
Dudley