I replaced the radiator in the 98 GT Saturday. While I was there, I wanted to fix the thermostat housing leak as well, so I sanded the thing flat and put it back on. All was good, it wasn't leaking... until about 10 minutes in to the burping process I notice it leaking out of the bottom, at a fairly good rate. Shut it off, squeezed the lower radiator hose and could see it coming out slightly above the thermostat housing. Figured it must be the water pump gasket. So I tore down the front of the engine yesterday to get to the water pump. While I was there, I went to pull the crankshaft sprocket off. At first I thought it moved a bit, but then I realized it didn't move at all, the whole crankshaft moved. Maybe 1/16 inch fore and aft. I'm betting that is causing the random misfired I've been getting...

Hmmmm......

 

I am not sure that is enough to say conclusively it's the cause.  but it is a bit concerning........do you get any noise like rod knock when you put the clutch in?