as long as their within about 20% of eachother you should be fine. a wet test shouldnt prove anything further.

Sounds like its only running on 3 cylinders. Get it running again and idling. Then remove 1 lead at a time then put it back on. when you reach the one that makes no difference in idle behaviour youve found the cyl with the prob.

Have you tried new plugs? Or even cleaning the old ones? Are all the leads 'clicked' in properly on each end?