I have a question for "Old Time H-Mod-ers", who out there remembers when SCCA changed their rules from 750cc to 850cc in H-Mod. I thought it was 63 or 64.

H-Modified was 750 cc from the Jurassic Period to end 1962 season; then 850cc till demise of the class end 1967 season. From 1968, D-Sports Racing took over.