I have an1953 8BA, bored 80, .425 Offenhauser Heads, Isky Max1, Mallory electronic distributor (no vacuum advance), Red's Headers. I put a Holley 390CFM 4160 on a Offenhauser single plane intake. The engine has about 600 miles on it and the idle characteristics are unacceptable. It an attempt to tune the carburetor I installed an A/F meter in the passenger header. The idle starts at 12-1400 RPM and after the choke opens drops moves to 800-1000RPM. This is fine, but when driven for a short distance and coming to a stop it will either return to 12-1500 or stall and become difficult to restart. I have a dedicated vacuum gauge on the dash and can find no vacuum leaks. I have read Holley 4160s are not very street able and am considering a Performer Edlebrock. I chose the Holley because the Flathead racers in the area suggested it, but they don't do much stop and go driving! And suggestions will be appreciated.