The Stovebolt Site Forums The Shop Area Engine Shop manifold heat? causing stumble/miss?!

well i have a 54 3100 with a 56 rebuilt 235 and i can't seem to get rid of this bad miss/stumble at mid throttle. everything on the engine is new plugs are a week old gaped at 35, petronix in a rebuilt distributor with new vacumn advance, accel high output coil, new wires, new fuel pump, filters, rebuilt the carb for the 3 time last week (soaked all parts in carb cleaner for two nights, blew all passages with compressed air over and over, checked everything 5 times, new kit installed and replaced the flathead body screws with allen to get the top nice and tight) carb doesn't leak anywhere not even on the throttle shaft. float set to 1-3/4", idle screw 2 turns out, #54 jet, timing at 5 degrees advanced.

the two things i noticed are "if" my dolphin gauge is reading correctly the truck runs around 155-165 degrees in the temp dept. i have a electric push fan in front of the rad on at all times, aluminum rad., new water pump and the stock engine fan. don't remember if i put in a 180 or 192 thermostat but i'm thinking 180. the only time the truck will get up to 180 degrees is sitting in miami summer traffic. the only other thing i can think off is the intake needing heat. it gets warm to the touch and pretty hot after the truck's been running a while. but i've seen so many stovebolts running well without manifold heat why shouldn't mine?

here a few pics of my current setup and my week old plugs as of this morning. #6 is rich while the other 5 are perfect?! what gives

http://i121.photobucket.com/albums/o235/marcelo54/DSC_0060.jpg

plugs are in sequence cylinder #1 to the right
http://i121.photobucket.com/albums/o235/marcelo54/DSC_0062.jpg

I would go 2-4 sizes larger on the main jet. Advance tyhe spark 2-3 more degrees. Make sure your accel pump has a good strong shot. If that doesn't do it try raising the float level 1-2 32's.

thanks for the response, i was thinking of raising the timing up to 8-9 degrees. i also have 56 and 57 jets laying around might give them a try.

went outside to do an oil change and while at it i disconnected the electric fan, and now the temp goes up to 180 degrees, seems to like it much better. on a bad note i did a compression test and #6 cylinder with the black plug only has 100psi while all the others are in the 145-155 range. since i had the head rebuilt(new valves, guides, springs, seals and shaved .08) around 2k miles ago, i'm guessing the rings on that cylinder are going. the shortblock was rebuilt by previous owner and is 040 over but no clue as to how long ago

I agree with wrenchbender, increase the size of the main jet. The headers will make it run leaner. Also, you probably don't need all that extra fuel line running that close to the exhaust manifold.
Fred