3919886 (Upper) Alternator Brace

[Henry J.]

I am investigating the 3919886 (upper) alternator brace, as I would like to acquire one ultimately. I understand it was used for 68-69 Corvette (427) (exc. P.S., H.D.) and for 70-74 Corvette (454) (exc. P.S.). My specific application is 1968 L36.

The 3919886 is a curved brace, 12 1/2" long, with a 6 5/8" slot and 2 13/32" offset. I suspect that the defining attributes are the extraordinarily long slot and the curved portion of the brace into which the slot is cut.

I would appreciate a picture of this brace before I start my search at the auto flea markets. I thank you for any help you are able to offer.

[Paul O.]

Re: 3919886 (Upper) Alternator Brace

There are 2 on fleebay with photos and parts label.

http://www.ebay.com/itm/NOS-GM-1965-74-CORVETTE-396-427-454-ALTERNATOR-TOP-AJUSTING-BRACKET-3919886-/400643307560?pt=Motors_Car_Truck_Parts_Accessories&hash=item5d4833b828&vxp=mtr

http://www.ebay.com/itm/Corvette-Alternator-Brace-Big-Block-w-o-Power-Steering-GM-NOS-1968-1974-/271268280917?pt=Vintage_Car_Truck_Parts_Accessories&hash=item3f28d97***&vxp=mtr

[Henry J.]

Re: 3919886 (Upper) Alternator Brace

Thank you, Paul.

I have viewed the pictures associated with both these listings. I find it difficult to believe that the slot length in either of these braces is 6 5/8". To my eyes, the slot lengths may even differ between the two.

[John C.]

Re: 3919886 (Upper) Alternator Brace

Henry

Where did you get the 6 5/8" slot length dimension from. The originals were much shorter than that. I measured the slot my 1968 and it is just over 3" long.

Original production braces also have an almost square end as shown in the attached picture. Later replacements have chamfers on the ends as seen in the eBay examples.

John

[Henry J.]

Re: 3919886 (Upper) Alternator Brace

John:

Thank you for your picture. The slot on my brace measures 3 7/16", but I know for certain that it's a reproduction of something, although I don't know of what.

The 6 5/8" dimension appears in various various Corvette P & A catalogues that I own, Group 2.317. When I first saw the dimension, I was astonished, as it's extraordinarily long. It may be a typographic error.

There are frequent posters on this board who collect these braces. Perhaps we'll hear from them.

[Joe L.]

Re: 3919886 (Upper) Alternator Brace

John:

Thank you for your picture. The slot on my brace measures 3 7/16", but I know for certain that it's a reproduction of something, although I don't know of what.

The 6 5/8" dimension appears in various various Corvette P & A catalogues that I own, Group 2.317. When I first saw the dimension, I was astonished, as it's extraordinarily long. It may be a typographic error.

There are frequent posters on this board who collect these braces. Perhaps we'll hear from them.

Henry------


I have NOS examples of the GM #3919886 brace. No need to picture them here, though, as they're the same as the ones shown on eBay. The reference in the P&A catalogs as to this brace having a slot 6-5/8" long has to be some kind of error. I can't imagine this brace having a slot that long at any time. That would mean a slot over half the total length of the brace! For one thing, there would be absolutely no need for a brace with an adjusting range of that length.

[Henry J.]

Re: 3919886 (Upper) Alternator Brace

Thank you for the confirmation, Joe.

After taking physical measurements of the reproduction brace on my car, I began to suspect an error. A 6 5/8" slot certainly would have made for quite an awkward piece, with questionable practical value. My reproduction brace appears to be rather true to the original, pictured by John, with the exception that mine has the bevelled ends, as John points out.

[Joe L.]

Re: 3919886 (Upper) Alternator Brace

Thank you for the confirmation, Joe.

After taking physical measurements of the reproduction brace on my car, I began to suspect an error. A 6 5/8" slot certainly would have made for quite an awkward piece, with questionable practical value. My reproduction brace appears to be rather true to the original, pictured by John, with the exception that mine has the bevelled ends, as John points out.

Henry------


The braces supplied in original service were probably of the original style (i.e with "straight cut" end). However, at some point that was changed to the beveled style. Most likely, this was some sort of "safety" improvement (i.e. to eliminate the "sharp" ends in a very accessible area of the engine compartment). Just when it occurred I do not know, but it's possible it occurred before the end of the use of this brace in PRODUCTION in 1974.

[Henry J.]

Re: 3919886 (Upper) Alternator Brace

Joe, you're making me feel even better!