[fordrodsteven]

Originally Posted by Freoway

Thanks for your suggestion. That sounds like a possibility although if the cam lobe on #8 had an issue, then I shouldn't get spark at the plug. Following on from what you said, I could also verify this by moving leads on the cap. I think there's enough play in the distributor rotation to shift the leads around to the next position on the distributor cap then rotate the distributor accordingly (45deg). I might try that.

Oh. I didn't realize you are getting spark at the plug. I assumed where it didn't affect the RPM when disconnected but the other seven did..... that #8 was not getting spark. Hmmmmmm - gotta think about this one a little bit. Odd that it should not stumble when you pull off #8 wire and it IS getting spark.
Yes I agree. I would try to move everything by one position in the distributor (hopefully there's enough room to do that) Then you will know if #8 still seems different or if the other cylinder is acting that way with everything in the new position. Let us know what you find after switching the stuff around. In the meantime I'm going to keep thinking this one through. If I come up with something I'll let you know.