'66 GM DOCUMENTED? "1 of 1"

[Richard S.]

Re: '66 GM DOCUMENTED? "1 of 1"

What's going on anyway....Dr.Rebuild, Paragon, and Long Island all show the 615 as correct for the 66 big block. Can they and the JG all be wrong???

[Richard S.]

Re: AND.............

AND the 66 Assembley Manual also shows 615 as the upper radiator hose.....what gives??

[Michael H.]

Re: '66 GM DOCUMENTED? "1 of 1"

Rick,

I suppose it's a result of the amount of research that has been done on this part by reproduction parts suppliers and NCRS. Obviously, it wasn't much. The original GM documentation shows the print for the 825. The assembly manual shows the 825. The "parts list" from engineering shows the 825. A March 66 printing of the parts book also shows the 825. There are several low mileage unrestored 427 cars that still have their original 825 hoses in place. Starting in 1967, the parts book listed the 3906615 as the correct hose for 66 and 67 so I suppose that's where everyone got the wrong number.

The 3882825 hose was a few inches shorter and did not have the "S" bend in the center. I may have a pic of one here somewhere. If so, I'll post it.

[Richard S.]

Re: '66 GM DOCUMENTED? "1 of 1"

Mike,
Page F373 of my 66 assembly manual shows the 615 as the inlet hose.......

[Michael H.]

Re: AND.............

If you look at sheet A1 in the L36 section of the 66 AIM, you'll see that the parts list includes the 3882825 uper hose with no revisions throughout the model year. No mention of the 3906615.

Sheet B1 in the L72 section, however, does indeed show the 3906615 upper hose but if we note the drawing date, 2/26/66, we learn that the entire drawing was revised and eliminated the 3882825 on or near that date. (actual change in production likely occured a month or two later) So, all big blocks had the 3882825 until at least March 66, and most likely much later, and at some point in late production, the 615 was used on at least L72 equipped vehicles.

[Michael H.]

AIM L72 Sheet B1

Look at the date of that drawing. Original release of 1 May 65 but redrawn and revised on 22 Feb 66. It then included the new 3906615 hose and no mention of the original 3882825.

If just a part number or two were changed, there wouldn't have been a note about "redrawn/revised but if several items or descriptions changed, the entire drawing would have been new and all of the old numbers and info would not transfer to the new drawing.

[Donald T.]

Re: '66 GM DOCUMENTED? "1 of 1"

I contacted the seller and asked him to provide pictures of his "GM documentation" showing it to be one of one. Not sure how a casual remark by Noland translated to GM documentation. Here is the response:

Hi,

Mr. Adams http://www.corvettemuseum.com/librar...of/adams.shtml has viewed this Corvette during a previous visit to our region. He believes this is indeed a one only car. Further, it is outfitted with the prototype a/c as seen in the factory manual. I will be glad to send you an attachment if AOL allows it.

Regards,
Kevin

[Richard S.]

Re: AND.............

My 66 is a June 66 car.....so 615 would have been installed originally????

[Richard S.]

Re: AIM L72 Sheet B1

I don't understand the point you trying to make here....can you please explain.

[Michael H.]

Re: '66 GM DOCUMENTED? "1 of 1"

Yes, that would be correct. Inlet to the radiator.

[Michael H.]

Re: AIM L72 Sheet B1

This is probably confusing because I refer to the L72 as changing to the 615 hose in late production. If we just concentrate on L36, which you have, we see that there was no change in part number, at all, for the upper hose to the end of 66 production. The 3882825 was used from SOP until the end of the 66 run, at least according to the AIM. Using this information, I would have to guess that the JG is completely incorrect if it states that all 66 427 cars used the 3906615. That just isn't the case.

If you're concerned about judging, bring AIM sheet A1 of the L36 section with you to show the judge. It clearly shows ONLY the 3882825 upper hose with no revisions for the entire year.

It is POSSIBLE that the 3906615 was used at some time in late production for the 390 HP L36 but it's not possible to document this.

If a reproduction of the 3882825 isn't available and you have to use a 3906615, I would then bring sheet B1 of the L72 section to BS my way through judging. It shows the 3906615 as far back as Feb 66, which would be prior to the time that your car was built. I'm getting confused now.

[Joe L.]

Re: '66 GM DOCUMENTED? "1 of 1"

Rick-----

If the 3906615 upper hose was used for any 1966 Corvette L-36 or L-72, I feel pretty confident that it didn't occur until very late in the model year. My guess would be that the PRODUCTION change occured in the April-May, 1966 period, if it occured at all. I expect the only reason that it even happened that soon was because there must have been some functional problem with the 3882825. So, I expect that the 3906615 was "rushed into PRODUCTION" for this purpose. Nevertheless, the 3906615 is, basically, a 1967 part number.

The GM #3882825 was discontinued from SERVICE in November, 1966 and replaced by the GM #3906615. So, until November, 1966 you couldn't even buy a GM #3906615; the GM #3906615 did not enter SERVICE earlier than the date of discontinuation of the 3882825, either. Of course, it could be that this was caused by GMSPO's desire to sell off the 3882825 inventory (which probably wasn't selling real fast at that time since the cars were so new). However, if there had been a significant functional problem with the 3882825, I would have expected that the discontinuation and replacement would have occured sooner.

The car in the eBay auction, assuming that the VIN tag is original to the car (not always a safe assumption) was built in November, 1965. There's NO way, at all, that such a car could have been originally built with the 3906615. That's the reason that I stated that the hose was incorrect; I was aware of the POSSIBILITY that very late cars were built with the 3906615.

Inasmuch as your car was built in June, 1966, I'd say that there's a possibility that it was originally fitted with the 3906615. Exactly when the PRODUCTION-line changeover occured for 1966, IF it occured at all, we may never know. But, IF it occured, it was late in the model year; that much, I feel very confident about.

The GM #3882825 is NOT reproduced, as far as I know. Since the part was discontinued in November, 1966, I doubt that there are too many NOS examples around (I don't have one, either). So, for all practical purposes, the use of said hose on a restoration is moot. Plus, if the JG says that the 3906615 is the correct hose, then that's the one you'd have to use, right-or-wrong. In this case, I think that it's a "blessing". Keep in mind that GM didn't change the hose, especially knowing what we know about this situation, because the 3882825 worked just as good.