We had the 454 in the 84 k-20 running good a couple weeks ago, but it seems that it has an intermittant miss on cylinder 8. It ran good and smooth for a long time but lately has slowly been getting worse and hasn't even left the shop yet. Has a brand new Accel distributor, good accel super coil, new accel wires, and ac delco plugs. We cleaned off the plug on cyl. 8 because it fouled out and seemed to run a little better. We checked the cap, no cracks and no apparent change between the terminals. We are stumped So she is leaving the shop tomorrow to go to another shop where we are putting a bigger lift on. I figure that maybe getting driven and reemed on a bit will clean it out and maybe sure the problem (hopefully). Has anyone else run into this problem before?