Aided by internet searches, it looks like the '55 Thunderbird 292 engine came in a P and M code versions, the M having lower CR and HP.  I found that the station wagons of that year came with optional T bird engines.  My '55 wagon's serial number starts M5RX.  The way it looks it has an M code T bird engine, and was built at the San Jose, CA plant.  If this is all correct, does someone know the specs for the '55 M code T bird cams?  Internet searches didnt yield anything.

The heads are ECG-C, 8.5:1,  but I still havent been able to see the block ID.  I think John M's site lists the ECG-C as being for a 272 with 4V.  However according to Holley they never made a 4V for '55 272s.

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.