running low lead kinda helps defeat the purpose. we ran av gas back in the 70s. 112 or 115 dont remember but it also had a high lead content which our heads at the time needed.ran a 12.5 .1 327 tunnelrammed with a 4 speed. . ran that same engine on the street and strip. and i drove it hard. sold the car in 89 and it ran as strong as when i first built it,