318 or 360? That is my question...

If your engine has lifter chatter, that would be the first place I would inspect.

If you're unsure about disassembling your engine, I highly recommend purchasing the book "how to rebuild small block mopar engines"

It's not terribly complicated as long as you read carefully and use a clean working environment.

At this point with having the same problems in the oiling system (all you mentioned is "issues"...that isn't very specific) I would say a full rebuild is probably ideal.

This way you can inspect all your block and crank's oil galleries with a long piece of flexible wire and make sure there are no blockages, the book covers this in some detail.

It will cost some money, but probably save a lot more than it costs in the long run.

Quite often when an engine is teared down the following things are best to be replaced.

Oil pump, fuel pump, water pump. gaskets, main bearings, big end bearings, cam bearings, piston rings, welsh plugs, hydraulic lifters, valve guides, valve guide seals

And often the valves should be lapped into the seats if the seats are in serviceable condition.

It is wise to have the block and cylinder heads surface ground at a machine shop to ensure they mate together properly, especially if the engine has overheated at some stage.

A regrind or aftermarket cam is also an option, depending on your budget.

If all these things are done, you essentially have a fully reconditioned engine.

Not only that but you will gain a ton of knowledge to go with your new motor, and you will have a blast building it.