Distributors and advance curves - how many did Packard build?

Posted by Jack Vines On 2010/6/16 20:52:04

Greetings, V8ers,

I just finished building an Autolite distributor with a custom Pertronix electronic ignition for the 364" V8 going into my E12 Studebaker pickup. This was necessary because last I checked, Pertronix did not have a fitment for the Autolite. They do have a bolt-in module for the Delco and I built one of those while I was at it.

In setting up the centrifugal and vacuum advance curves, I had to do a bit of research. I've found three different Autolite numbers and two Delco numbers.

Autolite IBJ4001B, C and D Was there an A?

Delco 1110865 and 1110873

Are there any others?

That there were five differing centrifugal and vacuum advance curves and two different initial timing settings indicates the Packard engineers were working to control pinging with the highest compression ratio in the industry.

Another thing I noticed was the shaft end play was on the high side of the already generous specifications. I shimmed mine back below the minimum. This will improve spark timing accuracy. When the distributor shaft can move up and down, the spiral gear advances and retards the timing.

Any current recommendations on spark plugs for the 374"s? Every time I learn a manufacturers numbering system and heat range system, they change it and discontinue those I recognized. Anyone tried the NGK plugs? Which ones worked for you?

thnx, jack vines