Since you have the engine out of the frame, pulling the crank might be a reasonable idea. When you do that the timing cover has to come off, giving you the opportunity to inspect the timing gear, replace the seal and install a speedy sleeve on the crank pulley if necessary, not to mention the gasket and the several 1/4" copper washers that go under the screws and get lost of forgotten when it was apart last. And of course you get a look at all the bearings and can replace them as necessary. Then there is the rear main seal, which always leaks, often into the clutch, especially if you just replaced the disc; otherwise it will go on the ground or the undercarriage. All of the above is far easier with the engine out of the truck. I have done all of these tasks in-frame, including pulling the flywheel and bell housing, usually in bad weather.
