[Ol' Ron]

Tuning a stock pre 48 distributor takes allot of guess work on the part of the tuner.driver. These distributors are well designed and preform very well when in good operation condition. BUT, ther is nor reference point, as to where the actual timing is. Adding a timing mark and pointer would be my first project. Most of these distributors have 20/24 degrees advance and is controlled by the Vacuum brake and this is a seat of the pants adjustment where you back off the piston to start with and drive the car around, adjusting this to prevent ping. It's nice to know how things work, hope this helps.