you have to start with a total cleaning so you can see anything, but the only course of action for a 283 with 167 thou on it is a rebuild, much of that external sludge is from blowby out the road draft and oil fill cap - even doing a complete gasket kit will require taking the engine out and finding a host of problems when you take it apart enough to replace all the gaskets, the rear main is leaking for one
Bill
