I was following this post because I knew I'd be pulling the water pump on my 71 Challenger 340 which I've owned since June 1972. I pulled the water pump yesterday and have looked at the bolts Scott has shown and mine has the same bolts. I changed the water pump in May 1974 but reused all the parts except the pump. My car has a build date of Dec 1970 at Hamtramck plant. Here's what I found. My fan clutch has a part number of 3462112 painted on it and has a blue seal. There's a white paint stamp on the fan which says "engine side". The bolts for the water pump also have nylon inserts drilled into the threads to lock the bolt in except for the top center bolt. That's what I've been able to check so far.
Terry