water pump

[Jeff Wilson (44821)]

What is the difference between the 330813 and the 330813P?
Thanks

[Joe Lucia (12484)]

Re: water pump

Jeff-----

Does the 330813P also have the "GM" trademark prominently displayed on the casting?

[Jeff Wilson (44821)]

Re: water pump

I do not see it on the picture at e-bay. I had never seen one for a corvette with a letter at the end of a number before.

[Joe Lucia (12484)]

Re: water pump

Jeff-----

I've not seen a GM pump without the "GM" trademark. It may be that by using the number "330813P", an aftermarket manufacturer is able to "skirt" infringement of a GM trademark (i.e. the number 330813 as applied to a waterpump casting) and, at the same time, imply that the piece is equivalent to the GM piece.

[Joe Lucia (12484)]

Re: water pump

Jeff-----

I did a bit more research on this one. It turns out that some genuine GM examples of the 330813 waterpump did have the "P" suffix after the casting number. I don't know what it signifies, though. However, I do think that these were later examples of the pumps (the 330813 was used from 1972 thru 1982) and I think that the "P" suffix examples were not produced in GM foundries. It's POSSIBLE that's what the "P" suffix denotes.

Keep in mind that the 330813 was a VERY low volume waterpump casting by GM standards. It was used only for L1972 thru 1982 Corvettes and some MD/HD trucks. I'm pretty sure that earlier 330813 castings were done at Saginaw. However, at some point, they may have decided that such a low volume piece should be out-sourced.

[Jeff Wilson (44821)]

Re: water pump

Thanks Joe, as always you have the scoop.