Here is the problem when it comes to water pumps, pulleys & fans. Over the years people change this stuff around for many reasons and most old Pontiacs end up with the wrong water pump or wrong pulleys. If you look closely at your engines pulleys and they do not line up absolutely PERFECTLY, I gurantee you someone along the way changed to the incorrect water pump ie: 8-bolt converted to 11 bolt and or short pump vs. long pump or vice versa.

Any of this can lead to running hot, throwing belts, wearing out water pumps and or alternators etc. A misaligned belt can cause lots of problems. This is what prompted me to round up all the correct parts for my 68. I went back to the 8-bolt water pump, correct pulleys etc. and once I did my car no longer through belts under high RPMs, everything lined up dead nuts and everything worked as it should! It's all about having the correct parts & pieces.

In addition to all of the above, people also have converted from the 8-bolt pump to the 11 and did so without out changing and getting the correct divider plates and or the two short little "tubes" that go inside the 11 bolt that are not inside the 8 bolt. So it's easy to see how over the years all of this stuff has gotten so screwed up on these old cars. The thing to do is take inventory on what you have (part numbers off the pulleys etc.), figure out what you should have, then find what you need and put it all back together the correct way and your problems with be resolved.

Vikki has a section of the shop manual on her web site that lists all the correct part numbers for all the pulleys for each year etc. Just be sure to look up the correct pulley as cars with a/c and or power steering etc. can list different part numbers. Look up the pulleys for your exact set up, then post what you need on here, try Frank's Pontiac parts etc. and locate the correct part numbers and you and your engine will be much happier!