Differences in '63 & '64 Differential Carrier Brackets.

[Irby G.]

Hi,
It appears that the only differences (besides ~$100) between the two are the 2 drilled holes along the top. Does anyone know the sizes of the holes and measurements that I could use to 'manufacture' a '63 out of my '64?
Aloha & Thanks in advance.
Irby

[Joe L.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Hi,
It appears that the only differences (besides ~$100) between the two are the 2 drilled holes along the top. Does anyone know the sizes of the holes and measurements that I could use to 'manufacture' a '63 out of my '64?
Aloha & Thanks in advance.
Irby

Irby-------


The 1963 and 1964 brackets did have different part numbers. However, I'd be surprised if the a deletion of the holes, by itself, would have caused a part number change. It's possible, of course, but it would be unusual. So, it's possible that there is some other difference, perhaps not easily discernable.

To be honest (and "heretical"), I would not use either of these early style brackets. If you do, check the side holes for any evidence of elongation. Even slight elongation can result in an unnerving "clunk" when starting out from a stop. That's why GM improved the brackets for later years (and SERVICE for earlier years). I recommend the 69-79 GM #3921657 bracket with reinforcing plates on the sides. Unfortunately, it's long-since GM-discontinued.

Now that I think about it, I'm not sure that the 3921657 bracket can be used for C2 Corvettes. There may be some other configuration difference (or, there may not be).

[Gary R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

I have one around here from a 63 or 64, in addition to what Joe stated they are thinner gauge metal then the later brackets. If there is something you want to me to look at let me know and I'll see if I can dig it up.

[Bob R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

I believe the only difference is the two holes you mentioned, they are for the emergency brake cable routing on the 63. The 64 has a different cable layout. You could drill the holes and have a usable 63 style bracket.

[Irby G.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Thank Joe and Bob...great. I think I'll look for the 3921657 bracket and use it except for judging. Before I did the tear down to start restoration, I seem to remember removing the emergency cable from that area. The bracket was in such bad shape I tossed it. I was more a novice then than I am now. I didn't realize that even if the part is crumbling, I should hold on to it. It still had value...if only for information.

Thanks Gary....if you could, measure on the '63 from the crease marked by the arrow in the picture to the center of both holes & also the size of both holes. I would greatly appreciate it. Thanks a ton.

[Gary R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

OK I will see if I can find it to see if it's 3 or 4, I don't recall other then the metal was way too thin for my use.

[Gary R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Ok I found it.
The holes are different size stampings. The back hole is .285" and the front one is .342" The lip to the back hole is .561" 1.030 center to center.

If you are interested in this one contact me.

[Wayne M.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Here's the TSB on this bracket:





c

[Gary R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Hi Wayne
I have to say that is interesting reading, but I have been able to drill through the front holes to convert them to the double through bolts the later diff's used. I wonder what the concern was not to recommend this? Core shift in the casting? The ones I drilled out were fine.

[Irby G.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Thanks very much Gary. That was just what I needed. Much appreciated.

Very Interesting read Wayne. I've seen a bracket with the welded washers on it before. I thought the guy had just rigged it up so it would work. I had no idea that is was part of a TSB.

[Joe L.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

Thanks very much Gary. That was just what I needed. Much appreciated.

Very Interesting read Wayne. I've seen a bracket with the welded washers on it before. I thought the guy had just rigged it up so it would work. I had no idea that is was part of a TSB.

Irby------


This style bracket was used for 1965-E68. It's better than the 63-64 brackets but not as good as the L1968-79 bracket.

[David R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

How would the judges treat a 63-64 bracket that had the bulletin performed? Would there be a deduct?

Dave

[Joe R.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

If the procedure has been performed correctly there should be no deduction, however I have never seen one with the safety wire installed. No deduction should ever be considered if it performed under a TSB. Those are safety issues.

JR

[David H.]

Re: Differences in '63 & '64 Differential Carrier Brackets.

How would the judges treat a 63-64 bracket that had the bulletin performed? Would there be a deduct?

Dave

David,

Section 4, item 15 of the Judging Reference Guide covers the Standard Deduction for Factory Recalls. It states a minimum deduction be made for originality i.e. not very much.

David