Thanks for the advice. I am pretty sure it is the origional fan, from the pictures in the manual. My father bought the '71 Z from the origional owner from San Diego over 15 years ago. It sat in his collection in his warehouse til he passed away 2 years back.So to my knowledge it was not modified in any way,til I got it. I stripped off the pollution control stuff and put a header and new exhaust,rebuilt the top end, and basically hooked up an I.V. to my wallet. I tried a flex fan after the first rad. blow up, but could not find a good fit. Same with an elec. fan- would not fit between pulley and radiator. I do not think there was front end damage earlier as all panels line up great, and we are friends with orig. owners who never admitted to a crash. has anyone found an after market flex fan that would fit? I have also replaced motor and trans mounts, so I don't uderstand where all this movement comes from. On a side note, on my way to the cruise-in last Saturday, the car stalled going around a sharp corner at a good speed(hey, it's a Z!) and died for the first time ever, then restarted fine as soon as it came to a stop. Then, when the rad. blew, the wipers turned themselves off and on for a second. I am beginning to think Dad is trying to tell me something-like slow down. Any one else have a haunted Z? Thanks again sblake, escanlon and eracer-hope to see you all on the road! Your online Z buddy, Craig