1970Olds442

Hello! I have a 1969 Oldsmobile 455 (39M181457 - no AC installed). I want to replace the water pump with a high volume pump. I initially looked at the aluminum FlowKooler 1775 pump but I see it is for 1971 Olds 455’s and above. I thought this was odd because it seems most parts for the Olds 455’s from the late 60’s to the early 70’s are interchangeable.
I plan on installing a March Performance Ultra Style Serpentine Belt Conversion Kit (part #16065) so I know I need a 6” ‘long’ pump. Will the aluminum 1775 fit my 1969 motor?
I’m asking because the March Performance kit requires a 6” pump and the FlowKooler pumps for the 1969 are 5 5/8” rather than 6”. Anyone have any information or recommendations on what water pump I should use on my 1969 with a MP serpentine belt kit? I would like to go aluminum and high volume but will go with whatever it takes.
Thanks!!
Ray

joe_padavano

The only difference between the 1970-earlier and the 71-later pumps is the diameter of the pump inlet. Just get the lower radiator hose that matches the pump.

As for the "serpentine" conversion, you are aware, I assume, that the March kit isn't really a serpentine design, since it does not use a reverse rotation pump. It's your money, but that's a lot of change for no performance benefits.

And if you do decide to keep the shorter pump, that would be Flowkooler 1776.