I'm working on a 56 Y-Block distributor.
I'd like to know where I might find the original specs for the dual diaphram adjustments?
Anyone know where these might be found?
Thanks so much
Jim

Not sure what spec's you want?  Are you wanting the correct advance readings vs Vacuum?  From a Sun Electric sheet for 1956 Fords - Ign.advance is 11-13 deg  @ .88"  &  22-24 deg. @1.73". 
Also Dist.rpm readings at 800 rpm is 5-1/2 to 6 -1/2 deg
                                     1200 rpm is 8-1/2 to 9-1/2 deg
                                      1600rpm is 11-12 deg
                                      2000 rpm is 13-14-1/2 deg
Above are Distributor degrees, not at the crank
Hope this is what you want?..

 



Paul

Hi Paul
I think that is Exactly what I'm after
Thanks you so much
Jim