I am trying to change the timing chain cover on my 400 engines as the water inlet/outlets are deteoriated. I've never removed the bottom pulley before and am looking for advise. Any advise on seals? Any advise on cover (new, used)and on alignment?

Pretty simple and straight forward. A decent original is fine or if you want to spend the dough a new one would be a good way to go. Only a couple seals involved. The crank seal and the two rubber collar seals that mate up to the back of the divider plate. My experience is with 69 so if your working on something different disreguard.

if you have an impact gun with a decent air supply the crank bolt should come loose fairly easily. the balancer should come off without much protesting but you may need a puller. felpro makes a timing cover seal set, and get the one with the repair sleeve for the balancer shaft. the rubber front seal eats into the metal...go figure. alignment is crucial to keep the front seal from leaking. there should be 2 alignment sleeves in the block when you pull the cover...if they are missing, you can get them.

I have found some variation in torque values between internet sites for timing cover to block torque values. What value has anyone used? Also, what have you used for the water pump. I will use an aluminum cover. Any suggestions on steel to aluminum interface?