1969 BB Distributor hold-down

[Steve Antonucci]

Hi,

This seems silly, but can anyone post an image of the "correct" distributor
hold-down and bolt for big blocks? Is it the plate version, or the bent clip
& plate combo? I can't say I've actually ever really looked until I needed to
install a restored distributor.

Honestly, every motor I have has come without one, or an aftermarket one.
How kooky is this request?

Steve

[Joe L.]

Re: 1969 BB Distributor hold-down

Steve-----

ALL 1969 Corvettes, big blocks, small blocks and, likely, even medium blocks if they had made any, used the distributor clamp pictured on the left of the 3 in the photo. The same clamp was used through about 1979 for all engines. For 1980, it was replaced by the clamp in the center of the photo which continued to be used into C4 production. Later in C4 production, the clamp on the right came into PRODUCTION use. Each of the clamps superceded its predecessor for SERVICE.

[Joe L.]

Correction

I had the middle clamp in the previous photo incorrect. So, I deleted that photo and I'm posting a new one here. These are the 3 stamped steel clamps.

[Greg L.]

Re: Correction

Steve, Here is the hold-down and bolt from my L36 built Jan 16/69.

[Steve Antonucci]

Re: Correction

Joe & Greg,

THANKS! That is exactly what I needed to see.

Joe, BTW, I did see one of them-there Medium Blocks on eBay today.
Good deal too!

Steve

[steve wallach]

Re: Correction

Ok, so for a 68 427/435 is one of these correct or should it be a wire clamp?

Steve

[Steve Wallach]

Re: Correction

Joe,

Which one of these hold downs would be correct for a 68 427/435 (Feb. 68 build) or should it still have the wire hold down?

Thanks,

Steve

[Joe L.]

Re: Correction

Steve-----

The clamp on the left is the one applicable to 1968, too. I wouldn't rule out the possibility that very early 1968 used the "wire" type clamp with retainer, though.

The "wire" type clamp with retainer was a, generally, "phenomenon" of the 63-67 period. Earlier V-8 used the same style clamp as 1968+.

I don't know why they ever went to the idiotic "wire" type clamp. However, wisely, they went back to the original V-8 style clamp for the 1968 model year and NEVER went back again.

[Steve Wallach]

Re: Correction

Thanks Joe,

My 68 DOES have the type to the left of your pictures, but I thought
pehaps it had been replaced with a later replacement, but apparently not!

Thanks Again,

Steve

[Carr C.]

Re: Correction

Hey guys,

This is an interesting thread.

I have a VERY original '70 LS5 convertible, with all of the "correct" bolts on the engine, and everywhere else, according to the JG. This car has the "wire" distributor clamp. The distributor is correct, the bolt is correct.

You're saying the clamp is not? Sounds fishy.

The car was produced on Feburary 19, 1970.

What do you think?

[Joe L.]

Re: Correction

Carr-----

I suppose it's possible that there was some situation in which the factory was trying to "use up" some old stock of the 63-67 style clamps. I HIGHLY doubt it, though. I can tell you fo absolute certain that the "wire" type clamp was not TYPICAL of factory production after, at the latest, early 1968. I doubt that judges would consider it original.

More likely, the clamp was changed at some point in the car's life. That doesn't mean that the bolt would also have to be changed----the original bolt may have been re-used. It may be that some previous owner or mechanic "preferred" the earlier style clamp (I don't know why, but people often have stupid ideas in their head) and, consequently, changed it. It's also possible that the clamp was replaced (e.g. the original was "lost") and the dealer sold the wrong clamp. There are all sorts of possibilities for an item like this.

[Mike E.]

Re: Correction

Joe--I may be redaing your response incorrectly, but my experience is that every 57-62 Corvette that I have experienced that had any kind of originality to it had the wire type clamp. Did I read incorrectly?
Mike

[Joe L.]

Re: Correction

Mike------

No, you read what I said correctly. I did a little more research on this and found that I was incorrect regarding the "wire" type clamp's usage being limited to 63-67 (and, possibly, early 1968). However, from what I can tell, the use of the "wire" type clamp did not begin with 1957. Here's what I found:

The stamped steel clamp GM #3704912 was used for 1955 through about the end of the 1959 model year. The 3704912 part number is also consistent with a 1955-issued part.

Beginning about the 1960 model year, the "wire" type clamp with seperate retainer came into use for most V-8 applications. This clamp was known as GM #3772532. The retainer used with it was known as GM #3770598. Both of these part numbers are consistent with about a 1959-issue. I don't see how they could have been used any earlier than that and certainly not as early as 1957. So, basically, I don't see how the "wire" type retainer could have been used much earlier than about the 1960 model year.

On November 1, 1960, the GM #3704912 clamp was discontinued from SERVICE and replaced by the 3772532 for all 1955-59 SERVICE.

The 3772532 clamp and 3770598 retainer then continued to be used in PRODUCTION through the 1967 model year for virtually all Chevrolet V-8 applications. As I mentioned, they may also have been used for very early in the 1968 model year. Parts like this do not necessarily change right at model year changeover.

In very early model year 1968, if not from the beginning of the model year, the GM #3704912 clamp was "brought back from extinction". This rarely occurs with GM parts, but it happened in this case. It was then used through about the 1979 model year for all V-8 applications. The GM #3772532 "wire" type clamp was discontinued from SERVICE in November, 1969 when SERVICE stock was exhausted and replaced by the GM #3704912 for SERVICE of most 1955+ V-8 applications.