Take the time and just pull the whole block. Your pan needs to come off to clean it completely. I've had several shops say that a teaspoon of antifreeze will trash the bearings on these motors due too its tight tolerances. Once it's out replace the spider injectors from the poppet style to the improved style and check the lifter valley and distributor gear.
I went through hell when my motor started to go. Good luck.
I went through hell when my motor started to go. Good luck.