Engine Oil Discussion

Don't change grade (weight) trying to control oil burning. It's not a good idea. Synthetic oils are great. Their only "drawback" with older engines that have leaks is, synthetic oil will tend to leak more, or "find" a leak where there may not be one, due to its excellent flow characteristics. It flows THAT good. Synthetics are made more for engines with modern rubber type seals for all of the gaskets and modern one piece rear main seals that have much less chances to leak. As already mentioned, your engine is probably ready for a rebuild if you're having these issues.