Referring to these handy charts, Sun electric showes what looks like two distributors, with two sets of advance for the 1956 Ford 272:
FDS12127A
Dist RPM Vac. Dist. Deg.
300 .15" 0-1/2 deg
400 .28" 1/4 - 1 1/4 deg
800 .96" 6 1/2 - 7 1/2
1200 2.21" 11 1/2 - 12 3/4 deg
1600 3.41" 14 1/2 - 15 1/2 deg
2000 4.60 " 16-17 1/4 deg
FDS12127B
300 .16" 0-1/2 Deg
400 .29" 0-1 Deg
800 .88" 5 1/2 - 6 1/2 deg
1200 1.27" 8 1/2-9 1/2 Deg
1600 1.73" 11-12 deg
2000 2.19" 13-14 1/4 deg
The Ford 1956 292 is identical to the second set above.
Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.