Could the 1 be an I , if so, it's a 3.73 Posi, they used the same code from ' 65 up to 69.The F 10 8 is the date code, June 10, 1968.Have you pulled the cover yet to look inside?
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' 72 Malibu project ACES # 1282 Team Member # 427
' 70 C-10 Pickup