Today I was cleaning up a Rams Horn manifold to take to the machinist, and noticed it has a casting number of ECY 6390 A.  So what year would that match  up with...'56 '57 or '58?  The C2TE is the casting number I have always heard.  My other RH is a C2TE. 

Both early and later units were exactly the same. 

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.