OK my 67 C/S 330 has air conditioning, looking to replace the water pump. Service manual shows pics of ones with and without A/C. The only visible diff seems to be
a circular identification boss (~top left side). Looked at local supply shops, some say with and some say without A/C. Question does anyone know if there is any mechanical
diff between the two?

 

I think the key issue is the pump length. Its likely either the 5.1" or 5.6" but I'm not positive. Check out this old thread that discusses pump lengths.

Water Pump Lengths - ClassicOldsmobile.com

 

All 1967 water pumps are 5.1". Expect every catalog you check to get this wrong.

 

I'll add that the correct water pump part number for a 1967 with A/C is 388183. That pump used casting number 384786.
Airtex AW773 is shown as an interchange for both that pump and the non-A/C version (388182). This is what I used on my 67.

 

Trust Joe for the length needed. There is a mechanical difference. The factory A/C pump has a closed impeller. The non A/C and most aftermarket replacements now have the open impellers. It is hard to say how much more water they move, it may be to prevent cavitation as much as more water movement. A/C and heavy duty cars have more overdriven water pumps compared to regular cooling, non A/C cars.

 

A bit of info on that:
I was worried about the cooling differences years ago, and after being unable to locate a closed impeller pump or a shop to rebuild an original, I installed a parts store reman with the open stamped impeller. I did not like doing it, but after many years of driving I have not experienced any cooling issues with the open impeller during 110º summer temps and running the AC. This leads me to the conclusion that the open stamped impeller is sufficient to do the intended job.

 

Joe- is the AW773 water pump open or closed impeller?
I have the 384786 (A/C pp just verified) But, bought a 3 core radiator from OPGI years ago (still in box) found out that after a phone call Between (OPGI and the Manufacture) that the Rad is "NOT"
for an A/C car. I'm not hooking up the A/C (but keeping all the crank and water pump pulleys the same). Trying to figure out what my options are?
Open or closed impeller with current radiator?

 

Like all new pumps, it has the stamped sheet metal impeller. A three row radiator with a 330 will be fine.

 

Thanks Joe, will go with the Open/stamped impeller water pump then. Was wondering on a way older thread you had, you had some pictures that gave very specific part numbers (say crank and water pump pulleys).
Where were those pictures from (factory papers?)

 

If you're talking about this diagram, this is from the Factory Parts and Illustrations Book.

 

Yes Sir, Spot on, is that book available?

 

http://www.t.gmpartswiki.com/getpage?pageid=90628

 

Thanks, will check it out

 

You are the designated cooling system tester, living in the desert. Yeah, I have not noticed any difference between the open and closed impeller designs as far as cooling. If you don't like having money there is this closed impeller pump. https://flowkoolerwaterpumps.com/pro...df1858c6&_ss=r At least Flowkooler now makes a billet impeller for their pumps, they use to rivet a plate to the open impeller. If anything, I think the riveted plate made the cooling worse on my 403.