early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

[David L.]

The 1964 Corvette AIM lists GM # 3854028 as the alternator brace with A.C. (exc. S.H.P.) but the drawing in the AIM (Sect. C60, Sheet C2.00) was redrawn and revised on 5/5/64. My 1964 Chevrolet Parts Catalog lists GM # 3846863 as the brace with A.C. According to Chevrolet Parts History GM # 3846863 was replaced by GM # 3854028 in May 1964 (service parts only).

Does the brace on the bottom of the first photo look like an early 1964 w/AC brace? On top is an original 3825463 brace used on 1963 Chevrolet w/283 & 327 engines and 1963 Corvettes with A.C. I have several of these braces and they were removed from 1963 Chevrolet passenger cars with 283 & 327 engines.

As shown in my 1964 Chevrolet Parts Catalog (Oct. 1963) the dimensions for the 3846863 are 12 1/8", 3 3/4" slot, and 1/4" offset. The 3 3/4" slot length and the 1 1/4" offset match with the brace on the bottom.

The dimensions for the 1963 Corvette brace w/AC, GM # 3825463 are 13", 3 1/2" slot, and 1/2" offset. The 3 1/2" slot length and the 1/2" offset match with the brace on the top.

Dave

[David L.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

Based on a shop drawing of 3755556, 3770360, and 3779210 generator braces in Noland Adam's 53-62 restoration book (page 247) I found how the length of the brace is measured.
The 63 w/AC brace (GM 3825463) matches up with the dimension in my Chevrolet parts catalog. The length of my "unknown" brace measures 12" which is very close to the 12 1/8" length as shown in the parts catalog for the early 64 w/AC brace, GM #3846863. The slot lengths check out as well.
Researching vintage Corvette parts is what this hobbie is all about.

Dave

[Richard S.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

You mentioned the 63 w/AC brace and the early 64 w/AC ,when was the 028 brace used? Was it an over the counter brace or used on the line?
My 64 A/C car has the one you describe as the 028, an end of Apr'64 build. Is that the correct brace for this time frame? Always thought this
was correct for my '64 250hp. Thanks

[David L.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

You mentioned the 63 w/AC brace and the early 64 w/AC ,when was the 028 brace used? Was it an over the counter brace or used on the line?
My 64 A/C car has the one you describe as the 028, an end of Apr'64 build. Is that the correct brace for this time frame? Always thought this
was correct for my '64 250hp. Thanks

Richard,

Do you know if the 3854028 brace is original for your April 1964 build?

According to my 1964 Chevrolet Parts Catalog (Oct. 1963) GM # 3846863 is the brace listed for 64 Corvettes w/AC (exc. SHP). For parts sold over the counter GM # 3846863 was replaced with GM 3854028 in May 1964.

The 1964 Corvette AIM lists GM # 3854028 as the brace with AC (exc. SHP) but this page was REDRAWN & REVISED on 5/5/65. There is no reference to the 3846863 because the page was redrawn. I am ASSUMING that the 3846863 brace was originally issued on the assembly line and for some reason the brace was replaced by the 3854028 brace, MAYBE because of a clearance problem since the 3854028 brace has an unusual shape.

I am hoping that other owners of 1964 Corvettes w/AC (exc. SHP) that have the original alternator brace would chime in to either agree or disagree with my assumption.

I believe that most, if not all, reproduction alternator braces are about 0.25" while original braces are about 0.20" thick. Over the decades I have collected a few Chevrolet and Corvette generator and alternator braces.

Dave

[Richard S.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

Hi David, I have owned this car since 1984, is this an original not sure, it measures .218 thick, are there any other markings to verify originality?

[David L.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

Richard,

I have never had a 3854028 brace so I do not know if there are any markings but with a thickness of 0.218" and by looking at the edge of the brace in your photo I would say it is original. The edges of original braces are somewhat slightly "rough". Does the slot measure 2 7/32" long?

My 3825463 brace measures about 0.212" thick and my NOS 3868882 brace measures about 0.205" thick.

Years ago I had an original 63 brace (without A.C.), GM # 3825462, and it was stamped with a large "V". I also bought a reproduction 3825462 brace just for comparison purposes and it did have the large stamped "V" but it was noticeably thicker (0.25" or so) and the edges were "perfect".

After looking at your photo the radiator hose looks very close to the alternator brace. MAYBE the 3825463 "early" 64 brace was much too close to the radiator hose so they replaced it with the 3854028 brace for additional clearance.

Dave

[Richard S.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

the adjustment slot measures 2 9/16
Ric

[David L.]

Re: early 64 Corvette w/AC (exc. S.H.P.) Alternator Brace

the adjustment slot measures 2 9/16
Ric

Ric,

I assume the 2 9/16" (2.56") measurement is from end to end. If so, the EFFECTIVE slot length is 2.56" - 0.18" - 0.18" = 2.20" or very close to 2 7/32" (or 2.22") which is what is in the parts catalog. The 0.18" is approximately the radius at each end of the slot.

I have 5 1963 Chevrolet & 1963 Corvette w/A.C. braces, GM # 3825463, with slots that measure 3.60" end to end which would have an EFFECTIVE slot length of 3.60" - 0.18" - 0.18" = 3.24". The slot length in the parts catalog is 3 1/4" or 3.25", close enough. In my very first post I stated the slot was 3 1/2" which is wrong, it is 3 1/4". Maybe I need new glasses.

Dave