I have had gear drives in my last 3 cars, both big block and small blocks. The sound was cool, and I got used to it. I never had one break anything related to the valve train, or see any adverse effects on it either. Now the new motor, being a strickly race motor, has a Jessel belt drive. I suppose if I was gonna build another street motor, I would put a chain drive on it. Hey, even the blower belt whine starts gettin to ya after a while, but it sure gets the blood pumpin. "Fun with cars"