If you don't drive in real cold weather, then blocking the crossover passage will help cool things off a lot. I usually just cut a piece of thin sheet metal as a block, I put it under the gasket, directly against the head. The vehicle will definitely take longer to warm up (carb, not temp) when the whether is cool. A thick fiber/plastic gasket under the carb will help prevent heat transfer to the carb. Make sure the gas lines are routed away from heat sources . The heat transfer plate and the under manifold insulation are good ideas as well. If you have an IR thermometer, you might want to check the actual temperature of the carb when the flooding occurs to be sure it is temperature related rather than pressure related. Bill Huff At 9/9/200910:55 AM, Mark Lindahl wrote: > > >Hi All, > >I have tried a few things to reduce/eliminate the boiling of gas in >the carb bowls after hot weather driving and shut down of 383. >Within a few minutes, the carb gets so hot that the fuel is boiling >and flooding occurs. I have seen it a few times. >The engine does not run hot during normal driving. Temp/Gas Guage >seem to be calibrated with temp guage around the 1/2-3/4 mark. >At idle and normal driving speeds, the engine runs strong. Newer >open chamber heads were installed about 18 months ago along with >hardened seats for unleaded gas. I reinstalled the original valley >pan and now have a 4 bbl. carb instead of the original 2 bbl. > >Here is what I have tried. >Installed gasket between hood and radiator support: It looks good, >but does not help my problem. >Installed new needle/seat in carb: Flooding still occurs, but somewhat less. >Waiting for stainless steel plate to install under carb to reduce >heat transfer: will advise. >I have removed the spring from the exhaust manifold allowing for >free movement of the valve: no change. >I took off the heavy metal air cleaner top and now have the air >filter exposed using just a flat top: no change. > >I also vaguely remember that some valley pans have the the heat >passages blocked off to not allow heat back up to the carb. >Since I don't drive the 300 in the winter or much when it is cold, >is this a good idea? > >Are there certain valley pans with the heat passages cut out and >some with them blocked off? >Any ideas would be helpful. > >Regards, >Mark Lindahl >'63 300 Conv. > >[Non-text portions of this message have been removed] > > [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: mailto:Chrysler300-digest@xxxxxxxxxxxxxxx mailto:Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/