3969811 water pump ZL:1 or copo 425 HP 427 ??????

[1969camarors427]

i have a water pump with a casting number 3969811 with a date code D 29 9, were these used on the 69 ZL1 engines as well as the L-72 427 engines, my book shows use in the 70 LS6 and LS5 engines but this is to early of a date, anyone have info on this one. thanks.

[x44d80]

Ed Cunneen's COPO Connection source book says casting number 3931065 for the Zl-1 waterpump.

[1969camarors427]

i just dug out the ed cuneen book and in mine it has no number on the page 97, but on page 98 it reds on the L-72 waterpump number it shows a 3931065 but in brackets a 23969811 which has the extra digit (2) in front of the pump is your book a different issue than mine. i cannot find it in the cars and parts v-8 casting number book for the use in 69 also. i thought i read something once about the aluminum pump on the first few ZL1 engines were equipped with a aluminum water pump with a 3969811 number the same number as the cast pump, i think it was the reference book but i cannot find it now.thanks.