The timing mark is on the flywheel. It's actually an imbedded steel ball. You time it from the right hand side of the engine through a veiw hole just above the starter on the bellhousing. You'll notice a pointer in the hole. Tip, paint the pointer white so you can see it easier.
According to the 1957 Truck Manual, the timing should be set at TDC with the advance disconnected and engine at idle speed.


Bill Burmeister