water pump question 66 L79

[William P.]

Can anyone please tell me what a water pump with casting number 3858826 or possibly 28 is used on. This pump is on my 1966 l79 engine that is being rebuilt.

Thank you

[John R.]

Re: water pump question

Are you sure it is not 3859326? That would be a correct casting for a '66 L79. Needs the 1/2 inch bypass and should be dated. Others can chime in....

[Joe L.]

Re: water pump question

Are you sure it is not 3859326? That would be a correct casting for a '66 L79. Needs the 1/2 inch bypass and should be dated. Others can chime in....

John and William-------


Yes, the number must be 3859326. In fact, GM #3858826 was a backing plate for the right front brake for 1959-64 passenger cars and 63-64 Corvettes.

The 3859326 is the correct pump for a 1966 L-79 with, as mentioned, a 1/2" NPT by-pass fitting.

[William P.]

Re: water pump question

Thank you for the replies. I will check the numbers again and let you know what I find.

[Joe L.]

Re: water pump question

Thank you for the replies. I will check the numbers again and let you know what I find.

William------


Casting numbers are notoriously difficult to decipher. "3", "5", "6", "8" and "9" are often confused.

[William P.]

Re: water pump question

Again thank you to everyone who replied. The 9 and the 3 were where the problem was so I used a large magnifying glass and have determined it is the correct pump.