Thanks for the help guys. So the capital letter i is used for the number one and is the last number of the serial number..ok tha works for me. The capital T is for Tonwanda plant. The 55 is for 1955 which seems right as the casting number next to the starter is C1055....so march 10, 1955. That last number is in fact not a number 7 but the letter Z. I scrubbed some more on the serial number and I can see a faint line that is certainly the letter Z and not the number 7. So the last question for you guys is what does the Z stand for? Thanks for all the help! You guys are great!