i never ruled it out. i did all the above plus new pertronix and coil and carb. trying to rule out the tranny. now i have a newer damper coming. and old trouble shooter for gm looked at it and said it was not a engine miss.So why have you ruled out an engine problem?
have you confirmed every cylinder is firing by a simple pull the wire out of the cap test?
have you pulled the plugs and looked at them?
have you done a compression test?
have you checked for a vacuum leak?