yes there is a 2 letter code in frt of motor also on the lifter valley pan there should be 00 for 400, 50 for 350 ,21 for 421, 28 for 428 ,55 for 455 also on the rear of motor there is a 7 dig code will let you know also
350=9790079
400=9790071
400 RA=9792506
428=9792968
455=9799140
these are just some of the casting codes
there are alot these are the 67 to 70 codes there are a few more also
Travis
travis williams
