To Michael Vath and 300 members, Since you have the 300C carburetors ready to install after being rebuilt, your 300C would run better if you could find and install leaner "metering rods". The following information was originally sent through the list server on July 5, 1999 by me. Chrysler issued a Confidential Technical Bulletin #364, dated July 18,1957, Subject Carburetor Performance - All Chrysler C 300-C. "We have received reports of poor idle quality, stumble or hesitation on acceleration, stalling on stops or sudden turns on some Chrysler 300C. Considerable improvement of warm engine performance can be obtained by following the service correction outlined below:" The Bulletin outlines an eight step process. In step # 7, they say to install (Carter #120-193) Chrysler Part #1631356 (.057") secondary jets in the front carburetor only. Use original secondary jets in the rear carburetor. Install (Carter #75-1160) Chrysler Part #1631394 metering rods in both front and rear carburetors. Make the preliminary idle setting by closing off completely the idle by-pass air screws of both carburetors. My 57 300 C carbs were modified in 1957 as per Bulletin #364. The idle by-pass air screws on my 300C have been completely closed since 1957. I have been using Carter # 75-1181 metering rods which are # 2 lean. Metering rods have three steps -- Economy, Mid and wide open. 1957 300C - Carburetor # 2534S & 2535S, Specifications #75-1263 is original 1957 .075" x .065" x .042" 1958 300D - Carburetor #2741S & 2742S, Specifications #75-1160 is 1958 Standard .076" x .066" x .048" #75-1180 is 1 lean .077" x .068" x .052" #75-1181 is 2 lean .078" x .070" x .055" The #75-1181 is for high altitude over 4,000 feet and will run smoothly at sea level. In a letter written by E.P. Carr, Car Engineering, Chrysler Corporation, to the original owner of my 300C, dated April 8, 1958, Mr. Carr states: Fuel economy at 4,000 feet could be improved by using our Altitude Package which contains one size leaner metering rods Carter No. 75-1180. My 300C has a good idle and runs very smoothly with the "high altitude" meter rods. The 300C was made to go fast and the Chrysler engineers richen the fuel mixture accordingly. The above Bulletin suggests #75-1160 for normal driving as the engine needs to be leaned. Hope that it is not too late for you to consider modifying your carbs as per above. John & Arlys Chesnutt, Portland, OR. 300C ----- Original Message ----- From: "Vath, Michael J." <mjvath@xxxx> To: <Chrysler300@xxxxxxxxxxxxxxx> Sent: Wednesday, February 20, 2002 11:21 AM Subject: [Chrysler300] Brisko's Mileage Saver - dealer installed? > My silly question for today: Is it likely that the pressure regulator on my C was a dealer-installed piece? > Its a Brisko's Mileage Saver (Exeland, WI). It has a glass bowl like the carb filters, and has 6 slotted screws on top. > > My local 80-something year-old carb guy says these were commonly installed by car dealers of old...and I should reinstall it with the rebuilt carbs. So before it joins the to-be-reinstalled parts pile, I figured I'd ask. > > Thanks! > Mike V >