I want to replace my water pump on my 69 Chevelle 396/325 with the correct pump. My engine date is T0109JK (Jan 9th). I have a chance to buy a core with the part# 3931065 cast date J78 or K88. Correct me if I'm wrong, but I beleive that J78 is Oct 7th 1968 and K88 is Nov 8th 1968. My question is what date is more acceptable to the build date of the engine? Should I try to find one that has a Dec date?
Thanks.

I have the original water pump (rebuilt now) on my 68 and 71. The 68 w/p date is 3 months before the motor date. and my 71 w/p date is 2 months before the motor date. If your motor is Jan 9th, the w/p can be anywhere from Oct thru mid Dec. and it would be acceptable...

Thanks Bill. I'm trying to collect the right parts before I start the restoration. I hope my car comes out half as nice as yours. You did a outstanding job. graemlins/beers.gif

I think I'm going to go with the K88 water pump.