Technical Pontiac water pump issue.

Well, there you go, that's good information. Good thing your gasket blocked that hole off, that could have been messy.

 

The reverse flow head setup was 55-59. The 4 bolt water pumps were 55-63 I believe. Then came the 8 bolt & 11 bolt pumps and their appropriate timing covers. The same pump is NOT used from 59 and up.

 

I believe probably so.

 

They changed the pump but the updated cover still fits the older 389. It will now have the later cover and pump which is suppose to work better. As I found out a common swap.

 

It is easy to look back and say, "I should have checked that first" but in the heat of troubleshooting shit like that will drive you crazy. Glad you got it.

Pontiacs are stupid. -Abone.

 

Does it have a water outlet at the back of the passenger head for a heater hose? I bet the heater would have worked good ! Glad you figured it out, and you will be happy with the newer pump.