I will be changing my 318 from a two barrel to a four barrel and swapping the cam and lifters. Since this involves replacing the gaskets for the intake, valve covers, timing chain cover, and the water pump, I am going to get a full gasket kit and change the rear main seal. It has been leaking a small nuisance drip of oil ever since I got the car (2 years ago) and I have been using a drip pan to catch it.
I will probably pull the heads to check the cylinder wear and bores since I don't know how many miles are on the engine. The compression is good on all cylinders and it doesn't smoke but I have no information on the engine.