My recently rebuilt engine(discussed in previous post) which runs
terrible but idles great, was just found to have a problem with the #3
cylinder.  After two days of thinking the timing was off, I finally came
to the conclusion(speculation) that a cylinder is weak.  There is no
acceleration and when pushed the car just bucks and jerks.  Well, I just
checked the plugs and all are nice and tan(insulator) with black around
on the metal, except for #3 which has a black insulator, clean metal
perimeter, and is loosing it's edges.  My thinking is that the rings,
which are new, are the problem.  Any other opinions?  The idle is so 
strong and smooth that I feel it is just this one cylinder and
everything else is really good(like new maybe).  Any help would be
greatly appreciated.

Thanks,
James Wagner