90 K5 TBI 350 (256,000 miles) just quit one day. Replaced sensors, fuel filter, removed and cleaned TBI. No difference. Figured it "jumped" time so replaced timing chain. Ran a little better but still runs very badly. Figure a valve was bent when it "jumped" time. Checked compression yesterday. All cylinders were 130-140 except #6 which was 90. I figure that is where my bent valve is. The other thing is that #2 was 180! It was also the only one where the spark plug was really oily and when I removed the compression tester is was really oily too. Questions: Am I correct in that this cylinder is not firing? So this means I'm basically running on 6 cylinders?? Why would this cylinder have so much more compression than the others?