70 Judging Guide re BB waterpump casting number

[Chris H.]

Hello,

I'd like to acquire the correct waterpump for my '70 454. The JG says "284"s are what should be on there, but other knowledgable (very) folks in this hobby state that the "960" is the correct one for late '69s and all of '70s.

I plan on having this car judged, and don't wan't to get wacked based on incorrect information in the JG.

I'm curious as to what peoples views are on this situation. Should I put a 284 on to conform with an error in the JG, on put an 960?

Is the date on 960s visible with the pulley installed etc? How would an 960 be judged with a casting date later than the engine build date (12/19/69)?

[Joe L.]

Re: 70 Judging Guide re BB waterpump casting numbe

Chris-----

All 1970 Corvettes with big block engines used a GM #3940960 waterpump casting. If the judging guide says otherwise, then the judging guide is incorrect. Unfortunately, I think that NCRS judges are bound to go with what's in the JG, so this could be a problem. I can't help with that part. What I can tell you is that all 1970 Corvettes with big block used the 3940960 unless an anomoly occurred. A '284' pump casting on a 1970, if it is original to the car, would be an anomoly and NOT typical of factory production.

Casting dates are generally not visible with the pullies installed. If the date were visible, you'd get 'docked' for a pump with a date after the engine's build date.

[Robert C.]

Re: 70 Judging Guide re BB waterpump casting numbe

Joe may be right as we rarely go by the book as casting numbers and dates aren't generaly judged. We look for the easy to read GM and the configuration of the pump.

[Jack H.]

Plus...

the reason the book is called a Judging GUIDE (instead of manual) is that it's intended as a supplement to the judge's personal knowledge. When a savvy senior judge knows the JG book is in error, he/she has every right to over rule the book and use their personal knowledge. Been there, done that....

That's one of the reasons that it's best to supplement your restoration efforts with on-field judging experience (attend a few meets and volunteer as an observer judge) instead of trying to interpret the JG books as an algorithm for how to properly restore your Corvettte. While the books are good (and get better as time passes), those who write and maintain them are only human and there ARE errors of commission + omission.

With a 'typo' or incorrect fact in the JG, you'd expect 'wrong' judgements to flow from the less experienced NCRS judges who rely on the books much more than Master Judges skilled in a particular year/configuration of Corvette. So, DO question what you read and don't blindly follow this/that just because it's in print or an 'authority' figure told you this/that.