When I was in high school my best friend had a 1970 RR with 440+6. We had to change the spark plugs in his car every Friday before going cruising. It is a bit of a big expense for us back then! I had a 426 with a factory cross ram in my car but I didn't have to change the plugs. My carbs were not as rich as his. Neither one of knew how to fix carbs back then, but we did know how to change the plugs.