1994 F-150 Driver

WuTang: If you don't have the tools necessary to perform the compression test on hand, then no I wouldn't bother. If you've got them, it wouldn't be a bad thing. A compression test can tell you a lot about your engine's condition, but if the first two are negative it's almost completely 100% that your gasket is good. So no you don't have to do the test.

Warlockk

Do a compression test. It's easy and you can borrow a tester from AutoZone. Also check for codes. That should be the first thing. It takes about 5 minutes and requires no tools. Oil in coolant often looks like soft brown mud like you are describing. While you are at AutoZone you can borrow a radiator test set and pressurize the cooling system. It should make any leaks easy to find. If it holds pressure no leaks and no head gasket concern to the cooling passages. Compression test will tell you about the combustion chambers. It should pump up and hold compression and all cylinders should be within about 10% of each other. If you get a low reading squirt a teaspoon of oil in the spark plug hole. If it goes up the rings are the problem. But check codes first.