Water Pump #3782608 - Date Code Question

[Ray K.]

Can anyone help me to identify the D2784 date code that's on this 3782608 water pump?
This water pump was on my '65 Coupe, which is a 327 / 300 with AC.

What's bothering me is the last 2 digits (84) being smaller than the first three digits (D27).
I haven't seen this date code scenario previously and I have no idea . . . .
Anyone have any ideas?
Thanks.

Ray K
NCRS Member #43777

[Harry S.]

Re: Water Pump #3782608 - Date Code Question

April 27, 1984 is what I see.

[Loren L.]

Re: Water Pump #3782608 - Date Code Question

Looks like a run of service replacement pumps for a widely used pump.

[Joe L.]

Re: Water Pump #3782608 - Date Code Question

April 27, 1984 is what I see.

Harry------


It's a mystery to me as I didn't think that the 3782608 pumps were being cast anywhere near as late as 1984. The PRODUCTION use of the 3782608 waterpump casting ended with the 1970 model year. Not too long thereafter SERVICE pumps for all 1955-70 short leg applications reverted to the 3859326 external bypass type pump which had the external bypass plugged for internal bypass application.

Also, note that the pattern number (13) implies a quite early pattern.

However, I suppose it's possible that GM cast these pumps for some special customer/application (e.g. Mercury Marine, etc.).

[Alan D.]

Re: Water Pump #3782608 - Date Code Question

Think we need some more photo's of that pump, top where bypass is, back, . . . A better picture of the "64" after a little cleaning, could it be a "6" (does not look like it)
If it is stumping Joe think more info is needed before any answers can be offered.

[Ray K.]

Re: Water Pump #3782608 - Date Code Question

Thanks for everyone's initial feedback. I'll clean it up a bit and send more photos soon . . .
Ray K

[Joe L.]

Re: Water Pump #3782608 - Date Code Question

Thanks for everyone's initial feedback. I'll clean it up a bit and send more photos soon . . .
Ray K

Ray------

Also note the small "T" to the left of the "GM". That undoubtedly signifies that this was a Tonawanda casting although it's not the usual format (i.e. "GMT"). That's even more strange because the Tonawanda foundry was permanently shuttered about that time. So, this would appear to be a Saginaw pattern that was used at Tonawanda to produce a waterpump casting that was otherwise long-since out-of-production. Very strange and very interesting. I'd love to know the history of this piece.

[Harry S.]

Re: Water Pump #3782608 - Date Code Question

That's what I figured also due to the two digit year code. Flint would just have a 4.

[Joe L.]

Re: Water Pump #3782608 - Date Code Question

All-----------

I wonder if Bill Mock has ever come across one of these?

[Michael M.]

[Timothy B.]

Re: Water Pump #3782608 - Date Code Question

I agree with Michael, to me the date looks like 64 not 84.

[Ray K.]

Re: Water Pump #3782608 - Date Code Question

Thanks to all who responded to my '65s water pump question . . . . .

Attached are a few more photo's of the 3782608 water pump after I cleaned it up some. It definitely is a Tonawanda pump with the date code being D2764/April 27th, 1964 (thanks Joe & Mike). I also talked to the previous owner and he could only recall purchasing it in York Pennsylvania, in the early 2000 calendar years, either from a Napa Auto Store or Apple Chevrolet.
If anyone has any more thoughts on what engine(s) these might have been used on, I would greatly appreciate it. I'll also give Bill Mock a call and see if he can shed any further info on it.
Ray K

[Joe L.]

Re: Water Pump #3782608 - Date Code Question

Thanks to all who responded to my '65s water pump question . . . . .

Attached are a few more photo's of the 3782608 water pump after I cleaned it up some. It definitely is a Tonawanda pump with the date code being D2764/April 27th, 1964 (thanks Joe & Mike). I also talked to the previous owner and he could only recall purchasing it in York Pennsylvania, in the early 2000 calendar years, either from a Napa Auto Store or Apple Chevrolet.
If anyone has any more thoughts on what engine(s) these might have been used on, I would greatly appreciate it. I'll also give Bill Mock a call and see if he can shed any further info on it.
Ray K

Ray------


Yes, this is definitely a Tonawanda version of the '608' casting. I could not see the ribs which are characteristic of Tonawanda pumps in your original photo. Also, as I look more at the date code, the first digit of the year does appear to be a "6", not an "8". So, this is simply a Tonawanda-produced version of the '608' pump. There's nothing remarkable or rare about such pumps. They were used on every internal bypass-type small block produced at Tonawanda from 1961 through 1968. That's a LOT of small blocks.