67 z/28 waterpump casting number

[Ron C.]

The casting number that is on the 302 waterpump should be 3858326 or 3998207, is that correct? Thats what in jerrys book but I have seen more 3859326 pumps. I was just wondering which would be correct for mid year 67 Z28s.

[Jon Mello]

Ron,

The 326 pump is the one to use.

-Jon

[jonboy1216]

which one is correct for a april built 68 z28?

[1968RSZ28]

which one is correct for a april built 68 z28?

3859326 like this one...

http://cgi.ebay.com/ebaymotors/67-68-69-CAMARO-WATER-PUMP-FOR-A-302-Z28_W0QQitemZ250539757171QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item3a55554e73

Paul

[JohnZ]

which one is correct for a april built 68 z28?

3859326 like this one...

http://cgi.ebay.com/ebaymotors/67-68-69-CAMARO-WATER-PUMP-FOR-A-302-Z28_W0QQitemZ250539757171QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item3a55554e73

Paul

That photo very cleverly doesn't show the most important part of the 326 water pump - the tapped hole in the boss on top for the bypass fitting. Original passenger car 326's had a 1/2" NPT hole for the fitting, but the overwhelming majority of 326 pumps were made for truck applications, and used a larger 3/4" NPT hole. Commercial rebuilders convert most small-hole 326 pumps to 3/4" NPT (since the biggest volume for them is for trucks, not cars), which ruins their originality value for cars, since you have to use a reducer bushing, which results in a deduction in judging. Beware any auction for a 326 pump that doesn't show the size of the bypass hole (especially when the auctiion says "no returns accepted" like that one does).

[1968RSZ28]

which one is correct for a april built 68 z28?

3859326 like this one...

http://cgi.ebay.com/ebaymotors/67-68-69-CAMARO-WATER-PUMP-FOR-A-302-Z28_W0QQitemZ250539757171QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item3a55554e73

Paul

That photo very cleverly doesn't show the most important part of the 326 water pump - the tapped hole in the boss on top for the bypass fitting. Original passenger car 326's had a 1/2" NPT hole for the fitting, but the overwhelming majority of 326 pumps were made for truck applications, and used a larger 3/4" NPT hole. Commercial rebuilders convert most small-hole 326 pumps to 3/4" NPT (since the biggest volume for them is for trucks, not cars), which ruins their originality value for cars, since you have to use a reducer bushing, which results in a deduction in judging. Beware any auction for a 326 pump that doesn't show the size of the bypass hole (especially when the auctiion says "no returns accepted" like that one does).

John -

Jerry MacNeish's "The Definitive 1967-1968 Camaro Z/28 Fact Book" states that the water pump installed on all 1967 and 1968 Z/28 engines had two slightly different designs; one with a 1/2" NPT bybass hole and one with a 3/4" NPT bypass hole.

Paul

[1968RSZ28]

That photo very cleverly doesn't show the most important part of the 326 water pump - the tapped hole in the boss on top for the bypass fitting.

I emailed the seller about the bypass hole on this water pump.  Here is his response...

Hi,
Yes it does have the bypass hole, it is 3/4 in.
Thanks

- ziggy-777

Paul