help with an engine miss

my 440 has developed a steady miss that I cant figure out. Engine has a noticeable miss at idle especially when in gear.When it first started missing I pulled the distributor cap to find the metal tab on top of the rotor button bent severly. I checked the distributor out and couldnt find anything loose or worn so I went ahead and changed the rotor button and started it up. still missing. I channged the plugs and none looked bad. Went ahead and installed new ones anyway started it and the miss was still there. replaced the wires with a new set of accell wires and it still missed. When i started changing wires i found corrosion on the distributor cap sockets where the plug wire plug into so I changed it out with a new one.Still misses....Im running out of ideas here and starting to get really frustrated.....

electronic or points? if electronic, look at ign. module. or try pulling off the plugs wires one at a time (and replacing after each test) to see which one if any does not have any effect on engine idle.

engine is electronic. I tried the feel each header tube for the cooler one all feel the same temp.......hotter than hades!!!!!!!!

Maybe an exhaust leak?

When you pull ed off the cap the first time did you remove any plug wires?? Double Check plug wire orientation and make sure that you got them all on he correct plugs.

I was pretty sure the firing order is correct but at this point I guess it wouldnr hurt to check it again.

5 & 7 are real easy to mix being next to each other in the cap, in the head and in the firing order.

After replacing the cap and rotor again with new pieces and checking the firing order at least three rimes I finally gave in and pulled the carb. The carb that was on there was a 600 holley with vaccum secondaries that I pulled off an old chevy beater truck because I could never get it to run right. Didnt want to use on the 440 but it was all I had available at the time. Pulled that one off and replaced it with a 770 street avenger and WOW!!! IT idles nice and pretty with no miss and the engine is alot more responsive...New carb still needs some tuning but well save that for another post.