Hy LeeBeckman, if you got an increase in compression by adding oil to the cylinders, that indicates worn rings. Excessive fumes from the road draft tube also indicate worn rings. Your compression could be artificially high because of carbon buildup in the combustion chamber. You did say that your plugs carboned up extremely quickly. I'm afraid that you are looking at an engine rebuild, I have a lot of respect for 283s, as I worked one for many years in my 57 one ton. Unfortunately 283s cost a lot more than 350s to overhaul, just because of parts availability and popularity. You could replace your 283 with a 350 with just a few adaptions, or you could have your 283 rebuilt, good luck.
