Hmmmm..I'm starting to think that this has something to do with the tranny now. There should be a vacuum modulator that controls shift points (I think). You said it doesn't bog when you shift it manually. BTW, anyone else feel free to jump in at anytime, since I don't know much about automatics. How's your tranny fluid? I don't know much about automatics, but if the bog doesn't occur when you shift it maually then I would look into the system controlling the shifts. Just a wild guess.
When you put in your Ignitor system, did you increase plug gap? I put that same system on my 250 and increased the gap to .055" I'm running an old Accel coil, but I'm going to switch it to a Pertronix coil and remove my resistor wire. The increased gap will help with mpg and give you a smoother idle. Hope this helps. John.
'68 C-10 - 250 with Edelbrock 600cfm 4 barrel, Offy intake, Hedman headers and true duals, HEI, MSD 6A box, relocated gas tank
Soon to have: T-5 tranny
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