1966-1967 Big Block Accelerator Rod Return Spring Bracket

[Mike B.]

Jack,

You've outdone yourself again with your animated graphics! I agree that if some were to modify the repro bracket then adding material would probably be the better choice. But I'd need to compare the two brackets by hand to see what kind of tilt the brackets have along their lengthwise folds.

Mike

[Joe L.]

t

Joe,

I'd like to hear from some of the '67 BB owners as to what style brackets were originally installed on their cars too. But seeing as though the title of this thread refers to 1966 I'm not confident as to any of them reporting what they have. But so far three 1966 L36 owners have chimed in stating that their brackets appear as the first photo that I attached in post #1. Here's a closeup of that shot and I can see a slight flattened bend in the bracket's forward end just above where the square boss would lay. I can see that Skip Steinmann's L36 bracket photo shows it laying above the boss in post #8 as well.

Mike

Mike------

That appears to me to be a "field modification" of the bracket likely performed at Tonawanda (with a file or grinding wheel). If so, in order to avoid this necessity, eventually the bracket was modified through a revision to the GM specs without a change in part number.

If the reproduction part manufacturer had used the modified GM drawing (likely since that's probably all that existed years later), they would have reproduced the bracket with the relief.

Also, consider this: if the reproduction manufacturer had known of both configurations but decided for such a low volume part they only wanted to manufacture one of the two, chances are they would have favored the 1967 configuration assuming that the bracket with the relief was in use by 1967. I consider the latter extremely likely since I highly doubt the bracket would have been modified after its PRODUCTION use ended.

I really would like to see some known-original 1967 brackets, especially at different points in the model year.

[John R.]

Mike, here is a photo of the bracket on the L36 with C60 with original engine. May be born with bracket, may not. I did not own the care since new. Hope it is of some help to your research.

John

[Mike B.]

Hi John,

Great to hear from you. I'm assuming that your above posted photo is of your '67 L36. Looking at my old NCRS '53-'72 Pocket Spec Guide I see an earlier '67 L36 uses a #3866948 cast iron intake just as the '66 L36 does. Is that your intake casting number? And there's that same square boss that your bracket wraps around nicely with its cut "step."

I think Joe Lucia makes excellent points in his previous posts to this thread about the possibility of a manufacturer modification to this bracket without a part number change. See his posts #4, 14, & 17. Your bracket may be original to your car? A handful of '66 owners have reported this bracket here without the "step" as the '66 TIM & JG states they should appear. I'm curious as to what the '67 TIM & JG states how this bracket should look like. And I'm hoping more '67 big block owners report the appearance of their brackets here.

Take care,
Mike

[Mike B.]

Hello All,

Our good friend and moderator Don Hooper was kind enough to edit the title of this thread for me to now include the 1967 model year. And thanks to Joe Lucia we know that this bracket is unique to all 1966-1967 big blocks. Bracket part #3876720. Since I don't have a '67 TIM & JG Don looked up whether that JG listed the same statement as the '66 JG does referring to the "step" in the bracket. Both manuals state that the "step" should not be present on the bracket lower edge.

Now that this thread includes both years hopefully owners with survivor cars will continue to report the appearance of their original brackets. I'm very curious of what information may be shared on this subject.

Mike

[John R.]

Yes Mike, the intake is the cast iron #3866948 and the casting date is D127. Car build is June '67. Good luck with your research.

John

[Owen L.]

Here is a photo of my original May '67 L36 as I was disassembling it last summer for rebuild. I've owned it since '79, so it's more than likely the original bracket.

[Mike B.]

Thanks John for the info on your '67s intake. Hoping all's well in JAX. Take care.

Owen, I don't see your photo. As of late I've been clicking on the paper clip icon to attach my photos. Worked okay for me. Looking forward to your pics.

Mike

[Owen L.]

Let me try again. (I'm finding the new forum confusing for posting pics.)

[Mike B.]

Thanks Owen for sharing this pic of your intake and accelerator rod return spring bracket. So far, between you and John Richter it appears that by the 1967 model year this bracket has the "step?" Maybe we can get more '66 & '67 owners to share photos of their brackets too?