Many months ago this group was quite involved in solving a problem with a freshly rebuilt 383 in my '65 300 Sport. The car would start and then promptly starve and die. That problem turned out to be a small oversight (error) I made when rebuilding the carb. I had reversed the metering jets causing the engine to die as soon as the vacuum pulled the metering rods down into the (now) smaller jets. The problem was identified and corrected as a result of this groups collective knowledge and experience. I have yet to register and drive the car at this point. Since that time the engine has continued to start and run but has never run well. It runs as though there is a miss at idle, the exhaust is somewhat blue (smoke), and if I crack the throttle it sometimes will pop. All these signs pointed toa vacuum leak. The intake was port matched to the heads and the valley pan gasket matches perfectly. I did inspect and replace the valley pan and found no typical signs of a leak. To be sure the new gasket was sealed I used a silcone gasket sealer on both sides of the valley pan gasket. There was no change. I have installed a Pertronix ignition with Fireball coil, new Taylor plug leads, new plugs, a new Edelbrock AFB carb, checked the cam timing with a degree wheel, indexed the balancer timing mark to TDC, checked the firing order, checked the fuel pressure, measured the valve clearance to ensure valves are closing, measured the compression (all cylinders are within 3 psi and strong), and adjusted the timing between 0 and 20 degrees initial. I'm back to thinking it's a vacuum leak, does anyone have any ideas? The car has the original manual brakes (for now). Does anyone know of any tricks to seal the valley pan? The heads have never been decked so there isn't enough room for additional gaskets to add on either side of the valley pan (intake) gasket. Do most builders even use silicone or just install the pan gasket as the factory did. I can't imagine how it could matter but I'm growing concerned that I may have caused a problem when I port matched the heads and/or intake to the original valley pan gasket. Any thoughts? I need to drive this car this summer and I'm getting near the end of my rope dealing with the bugs on this engine. It ran like a champ in 2001 when I drove the sad looking beater back from California. I should have left well-enough alone and lived with the cracked ring for a while. Thanks guys! Ryan Hill in Vancouver, Canada. _________________________________________________________________ Windows Live Hotmail gives you the control you need to help you keep your e-mail private, safe and secure. See for yourself! www.newhotmail.ca?icid=WLHMENCA147 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/