63 shroud bracket flat washer

[Michael G.]

Flat washer part number 3748358 is used in three places to attach the upper radiator bracket on 63 cars. Does anyone have a print or know the outer diameter of this part?

Thanks,

[Kenneth S.]

Re: 63 shroud bracket flat washer

My list shows it as a stamped steel 5/16" flat washer but black phosphate.
Ken

[David L.]

Re: 63 shroud bracket flat washer

Mike,
I can not find anything in my 1963 Chevrolet parts catalog (Oct. 63) or in any of my other Chev. parts catalogs and it is not listed in my 1963 price schedule (May 1963). However, the 3748358 washer was also used on the automatic transmission control linkage of a 1967 Camaro w/M35 as shown in the 67 Camaro assembly manual (UPC M35, sheet A8), also a 1965 Chevrolet w/M35. The washer attached to the swivel. The washer was also used on the 1966 Corvette shroud bracket (UPC 11-13, sheet A5) and the spare tire cover (UPC 10, sheet A2). When I get a chance I will check the washer size on my 66 Corvette.

Why don't you remove the spare tire cover on your 63 Corvette. There are four 5/16"-24 X 1/2" bolts (GM # 171110) and four 3748358 washers. The 66 Corvette has four 5/16"-18 X 9/16" bolts (GM # 9420825) along with the four 3748358 washers.

Dave

[Michael G.]

Re: 63 shroud bracket flat washer

Niether of my cars has a black phosphate washer. Everything is zinc plated. The bolt and washers on the right are new Paragon repops, the ones on the left are from my car.

[Michael G.]

Re: 63 shroud bracket flat washer

David, The car is about two hundred mikes away, so looking at the spare is gonna be difficult for a few days.

Anybody know the correct outer diameter of the part in question?

Thanks,

[Ronald L.]

Re: 63 shroud bracket flat washer

Back to the top - I have the same question in both places - washer size - anyone?

[Michael G.]

Re: 63 shroud bracket flat washer

Ron,

The attached photo is from an untouched 28K mile car. This washer is identical to the small one in the photo I posted earlier in this thread. The earlier part is from my Duntov car, so I'd say those are two pretty good indicators that the original washer was .875 inch O.D. and the bolt has an "L" head marking.

[Ronald L.]

Re: 63 shroud bracket flat washer

Thanks Michael, that is what I was looking for, the OD, 7/8".

L head mark for 63, by 66 they used bolt 122007 which was used all over the 66 cars and "one" head mark on known original cars has the RSC head mark. Would great to find other head marks because those RSC's are hard to find.

[Joe L.]

Re: 63 shroud bracket flat washer

Flat washer part number 3748358 is used in three places to attach the upper radiator bracket on 63 cars. Does anyone have a print or know the outer diameter of this part?

Thanks,

Michael-----

GM #3748358 was never available as a SERVICE part and I have no specification information on it. The fact that it has a Chevrolet part number might indicate that it was in some way "special" and not otherwise available in the "world" of GM Standard Fasteners or it may be a fastener that was otherwise available in the "world" of standard fasteners but received a Chevrolet part number anyway.

[Michael G.]

Re: 63 shroud bracket flat washer

The other part of this question is why many of the cars I've seen also use this washer in six other places to attach the radiator shroud. The build documents don't call for it there, they just show a split ring lock washer, yet some ostensibly correct vehicles seem to have them there.

Anybody know if the flat washer is supposed to be on those other six shroud attachements for 63?

Thanks,

[Ronald L.]

Re: 63 shroud bracket flat washer

Michael,
The other key with these washer is the thickness.

When I pour over the thickness, they are all over the map, but for example, this washer is used several other places on the car so for a given car unless its built with repro-wrong stuff, you will find consistency in this thickness.

Let me knwo what you see there, I'll measure mine tomorrow.

[Michael G.]

Re: 63 shroud bracket flat washer

Ron, I don't have a car nearby today, I'll measure it on Monday. Mike