Which water pump needed for '68 Z28

[dannystarr]

This is a VO523MO Engine with an aftermarket water pump. What pump should be on this engine, and what is the acceptable date spread. I see numbers in Jerry's Book. But I am a little sketchy on the inlets and out lets, 1/2" 3/4", Bushing, No bushing, to late for 326?... Anybody got a picture of what it SHOULD look like... Danny

[x66 714]

The correct pump will have 1/2" threads & no bushing...Joe

[1968 Z28]

Hi Danny.....At one time I was asking the same questions that you are now asking.  Back in the 80's, I had replaced my water pump with a rebuilt one that had a different cast number and had the 3/4" bypass output.  Several years ago I started looking for the correct pump that would be right for my car.  Well finally....after looking all this time, I found a 326 pump with a 1/2" bypass output on eBay that seemed right for my engine.  My engine build date is 06-19-68 and all of the engine components have casting dates in the first week of 05-68 and the pump I found had a casting date of E-1-68 so that is what I am going to use.  I don't think I will ever find another one that would be any more acceptable than the one I found.

Hope you can find an acceptable one as well.

[dannystarr]

Gotcha, but I was wondering when the cut-off was for the 326. Since this is a late in May assembled engine... would it still have a 326? Anybody know? ... Danny

[bertfam]

Yes, it would have the 326 pump. The 1969 model year went to the "long" pump, so all 68 302's would have used the 326.

Ed

[dannystarr]

Thanx Ed, short Pump 326 it is... NOW, what is the acceptable time date spread?... Danny

[bertfam]

NOW, what is the acceptable time date spread?

Up to several weeks, but usually they were only a few days to a week or so before the engine assembly date.

Ed

[68camaroz28]

I believe that water pump was used on trucks also and the reason for the 3/4" size along with when they went to re-man outlets they were mostly changed to the 3/4" size. JohnZ mentioned the re-man issue before if my memory is correct.

[z28z11]

For your consideration - I picked this pump up ($15.00) in a local swap meet a few years back, thinking it was correct for my '68 due to the date, bypass, short design, and instruction sheet, but after reading the previuos threads I have a severe case of doubt. Looks appropriate, but maybe not -

Nice pump for the price, anyway.

Regards,
Steve

[z28z11]

Last two pics.

Also, note the instructions in the sheet above. This pump appears to be NOS, not a reman, plus no signs of ever being bolted on an engine. I could not find the part number in my '74 printing parts manual. Bag containing the 3/8" bypass plug, two gaskets and a 3/4" square head pipe plug were (are) in the box -

Regards

[bertfam]

According to CBTN (1960-1964), that pump was "used randomly on late 1963 and 1964 Corvette high performance engines. The reason for this is unknown and is still being researched". It also appears that it may have been used as a generic service replacement.

Ed