I have been doing a lot of work on my 1969 W31 and have pictures to post but my phone not agreeing with my computer. My car has water pump # 4089287 with the KA pulley w31 balancer and 2 groove lower pulley. HD cooling radiator EC V01 4 core. Power steering unit with 4 engine mounting locations. Problem I am having now is the P/S belt has no clearance and rubs the KA pulley. P/S pump has to be correct with correct spacers on front of block, motor mount of block and exhaust manifold. Double and triple checked and cannot figure out why I have no clearance or how I am going to get any clearance from belt rubbing the KA pulley. The P/S belt runs from the crank pulley to the pump using the balancer forward most groove, (Doesn't go to water pump) The front groove on water pump goes to alternator and back crank pulley. The rear groove of KA pulley is not used. If anyone knows what water pump is correct that will help. One on car now is 4089287.

 

Thanks to 442Fred we were able to figure out the car had the wrong water pump. Had 5.1 inch and needed 5.6 inch 400269 pump. Seems there are at least 3 pumps used on Oldsmobile engines and pulley combinations. This car has had wrong pump and fan belt configuration for over 20 years.

 

Olds water pumps come in 5.1", 5.6", and 6.1" lengths, with additional variations in the inlet diameter. The pulleys, brackets, and pump all need to be used as a matched set.