So my truck has around 175k miles. I've changed the tranny fluid regular and all the normal stuff along with all ball joints. My water pump seems to be leaking (getting antifreeze spray on the windshield) and it looks to be blowing out under the alternator somewhere (edge of the water pump). I was planning on changing out the timing chain while I was at it but wasn't sure if there was something else I should do while I was at it. I remember reading about some part that should be replaced that had something to do with timing and could wreck the engine if it went out but can't remember what it might be, some part on top near the firewall. Great little truck I've been running for 14 years and want to keep it going.

Thanks