[Joe B]

I am trying to locate the proper dated engine for my goat it is suppose to have a september built 1966 400 what is the proper letter designation for september? I was told that I and J may not have been used but I do know that M is december 1966 the only year that used M for december any help would be great
Thanks Joe

[i4abuygto]

Joe B - are you looking for a 66 block or 67 400? The year that was not in sequence for September was for the production year 1967. The letter "L" signifies December for all years but calendar 1966 (1967 model) when the letter "M" was used for December. Since "I" was used in all years, it is possible that both "I" and "J" were used to designate September.This website should help http://nextgenparts.org/updatedsingl...pontengid1.asp

[Joe B]

The web site info is great it confirms a lot of mystery to me for 1967 model year blocks cast in 1966 the 'I' and 'J' date code designation are possibly used for september because I know that 'M' was used in 66 for the month of december so that left a big mystery for 'I' and 'J' for september thank you very much this certainly eases my discomfort
Joe B

[i4abuygto]

I am glad that the information was helpful. I am new to these posts but have been aquiring 67 parts to restore my goat for over 20 years. I wish you well with yours. Have fun.

[bobbyj1]

My september 66 build date 67 GTO had a J date coded block, heads and intake. Block verified as original by PHS.