Part number help, ring and pinion & intake gaskets

[G A.]

Hoping someone can confirm four part numbers. The R&P box has 3961421, the ring is 3733908, pinion is 3885945. They appear to be 4.11's from the tooth count. Are these correct for a '69?

Intake gaskets are 3940903. I know they are square ports, just curious if they are period correct or later 'service' replacements.

Thanks!!

[Wayne M.]

Re: Part number help, ring and pinion & intake gaskets

Hoping someone can confirm four part numbers. The R&P box has 3961421, the ring is 3733908, pinion is 3885945. They appear to be 4.11's from the tooth count. Are these correct for a '69?

Intake gaskets are 3940903. I know they are square ports, just curious if they are period correct or later 'service' replacements.....

Dan -- to answer the 1st of your questions, yes, my Jan 1970 P&A30B catalog shows 3961421 as correct for 1965 thru 1970. The number on the box is the 4.11 part # for ring 3733908 and 3885945 pinion, per the parts book. Was this the eBay item that suddenly disappeared from the listing a day or so ago ? I was watching it to see what it would go for (got one too many 4.11's myself ).

[G A.]

Re: Part number help, ring and pinion & intake gaskets

Wayne, thanks and yes this is an ebay listing. Funny but I still show it as active. Would you like a link? Also, would you be interested in selling one of the too many?

[Joe L.]

Re: Part number help, ring and pinion & intake gaskets

Hoping someone can confirm four part numbers. The R&P box has 3961421, the ring is 3733908, pinion is 3885945. They appear to be 4.11's from the tooth count. Are these correct for a '69?

Intake gaskets are 3940903. I know they are square ports, just curious if they are period correct or later 'service' replacements.

Thanks!!

Dan------

The ring and pinion set, both in terms of the gear assembly part number and the individual gear part numbers, are for a 4.11:1 ratio Corvette gear set. The assembly part number was first used for later 1969 Corvettes but the gear set will function perfectly for any 1965-79 Corvette application.

I cannot find much information on the GM #3940903. It looks to be about a late 1968 released Chevrolet part number. However, I can find absolutely no application information on it and it was never cataloged for any Corvette or other Chevrolet application I can find. In fact, all I can come up with is that it was discontinued without supercession in July, 1992.

[G A.]

Re: Part number help, ring and pinion & intake gaskets

Thank you Joe,
To expand further there is a part number to the 'package' of the gaskets, 3955527. The reason I did not include it is I'm not sure the package belongs to the gaskets.
3940903 is pressed into the gaskets and the china wall rubber gaskets have GM on the small tab protruding from them. Also, the tab is a semi-circle shape, not the rectangular shape I have seen.

[Joe L.]

Re: Part number help, ring and pinion & intake gaskets

Thank you Joe,
To expand further there is a part number to the 'package' of the gaskets, 3955527. The reason I did not include it is I'm not sure the package belongs to the gaskets.
3940903 is pressed into the gaskets and the china wall rubber gaskets have GM on the small tab protruding from them. Also, the tab is a semi-circle shape, not the rectangular shape I have seen.

Dan-----

OK, the GM #3955527 gasket set is a set first released for the 1969 model year for big block, rectangular port applications (except HD). It was used for big block rectangular port applications through 1971 when the rectangular port era ended for PRODUCTION engines. The GM #3955527 gasket set also was the SERVICE gasket set for 1965-68 big block, rectangular port applications.

I'm actually surprised that the GM #3940903 was ever available separately. As a matter of fact, I can find no indication that it ever was available separately except the fact that it was discontinued in 1992. For it to have been discontinued under that part number it had to have been somehow available separately. No matter, though.

[Wayne M.]

Re: Part number help, ring and pinion & intake gaskets

..... there is a part number to the 'package' of the gaskets, 3955527. The reason I did not include it is I'm not sure the package belongs to the gaskets.
3940903 is pressed into the gaskets and the china wall rubber gaskets have GM on the small tab protruding from them. Also, the tab is a semi-circle shape, not the rectangular shape I have seen.

Dan -- I have a pair of those 3940903 intake side gaskets, part of a (head) gasket "unit" Gr 0.289. #3957990. See thumbnail below big pic.

The intake numbers big pic below (gasket unit set #3917955) included both oval and square port numbers. Zoom in to read # 3860402 for the square port. Ignore the marker over-write on the package. Stands to reason that these gaskets are a lower part number than the 3940903.

So judging from the Oct '67 and the July '69 catalogs I have, the imprinted square port part number changed to the one you have.

[G A.]

Re: Part number help, ring and pinion & intake gaskets

Joe and Wayne, that's what I needed to know! Thanks gentlemen. And Wayne, if you want to sell a set of those 4.11's please let me know. My car had a set of 4.56's installed years ago and I'm anxious to get the 4.11's.

Dan

[Wayne M.]

Re: Part number help, ring and pinion & intake gaskets

Joe and Wayne, that's what I needed to know! Thanks gentlemen. And Wayne, if you want to sell a set of those 4.11's please let me know. My car had a set of 4.56's installed years ago and I'm anxious to get the 4.11's.

Dan

Joe & Dan --- just checked the stampings on my 4.11 set and they correspond to the above posts: ring 3733908__9 37___GM__8-73__2; and the pinion end (first line) 3885945___GM 2; (lower line) 9 37___1 73.

So this gearset was produced in 1973. Did any 1974-up Corvettes offer 4.11's as a production ratio ? This one is obviously service as installed in an early '69 diff stamped for 3.08 posi .

Dan -- I'll send you a PM.

[Joe L.]

Re: Part number help, ring and pinion & intake gaskets

Joe & Dan --- just checked the stampings on my 4.11 set and they correspond to the above posts: ring 3733908__9 37___GM__8-73__2; and the pinion end (first line) 3885945___GM 2; (lower line) 9 37___1 73.

So this gearset was produced in 1973. Did any 1974-up Corvettes offer 4.11's as a production ratio ? This one is obviously service as installed in an early '69 diff stamped for 3.08 posi .

Dan -- I'll send you a PM.

Wayne-----



1974 was the last year that a 4.11:1 rear ratio could be ordered on a PRODUCTION Corvette but only when the Z-07 package was also ordered. The same was true for 1973. During the 1973 and 1974 model years a total of 92 Corvettes were ordered with Z-07. How many of those 92 cars were equipped with 4.11:1 is anyone's guess, but I'll bet it was a very small number.