Quote: Yes I've seen those as well (the "23" bolts) just never on an original 340 Careful consideration needs to be given when talking about different years because hardware and assembly methods varied a lot (even within the same year) especially in 1971 when the engine plant changed fro Windsor to Mound Road (when the engines went from Orange to Blue paint). Ill be posting more pics of various bolts Ive found on my 71 survivor engine this week.
Oh, so moving the production to Mound Road was when the color changed? What date was that? My car was built 10/71. Yet, the casting date on my 340(original block)is 1/71.
Careful consideration needs to be given when talking about different years because hardware and assembly methods varied a lot (even within the same year) especially in 1971 when the engine plant changed fro Windsor to Mound Road (when the engines went from Orange to Blue paint). Ill be posting more pics of various bolts Ive found on my 71 survivor engine this week. 
