I have a 305 Crusader that has started to some burn oil. I added some Barttol to the oil and the blue smoke or exhaust appears to have stopped. I know that in the next couple of years I will either have to repower or rebuild. How hard would it be to convert the 305 to a 350. The marina mechanic told me that it does not get run enough maybe once a week and that it is either the rings or the oil seals. The engine was rebuilt about 8 years ago are both lower and end and heads. They did not pull the pistons at that time to check the rings.
