[PbFut]

You can remove the timing cover without removing the pan but you need to drop the pan in the front as there is a lip the cover needs to clear past on the pan. I lossen the rear couple bolts on pan and remove forward bolts. That will give you enough room to work assuming you have good rubber gasket not stuck. It sounds like your engine is older so dropping pan is probably going to be necessary.
If rubber is bad on balancer, you must replace.
If you are getting slop on rotor, your chain and likely sprockets are bad. If the distributor is as old as the truck, replace it. Your walking timing is indication distributor is loose or the chain is just that sloppy. Go to summit and build your project on their site either in the cart or create wish list to track your budget. For general street use, summit brand parts are reasonable choice. The part will have been vetted by many customers before you so fit and quality will be decent.