72 Small Block Vaccum Advance #

[Edward J.]

I know the JM stated a no 437-16 canister no. but the one on my dist is a 437-15 which I beleive is orig. to car, could it be a possable there were other numbers. I seem to remember a discussion on this topic before, but looked could'nt find it. thanks Ed.

[Terry M.]

Re: 72 Small Block Vaccum Advance #

Yours is probably OK.
When we added the VAC information to the TIM&JG we used the Delco Spec books for the data that we did not have from experience with cars, and apparently some of them are not quite accurate.

Hopefully a few others with original VAC actuators on their distributor will post up here so we will know if 437-15 is correct or if there was more than one variety.

[Kurt G.]

Re: 72 Small Block Vaccum Advance #

Not only possible, but probable. As I've posted before, my '72 small block is all original, but, it has a carb specified for a pickup; exhaust manifolds that are correct for a AIR car, but has no pump. I've found several other anomolies, all correct as installed on the car in St. Louis, but anomolies per the JM for the car. Don't sweat your.

[Don L.]

Re: 72 Small Block Vaccum Advance #

Edward, It was me that started the recent thread on this subject. After a bit of confusion, I have concluded that the "16" is a measure, not a part number. I will admit that I'm still a bit confused on this, however, I have read enough, and seen enough evidence from original cars to conclude that "437 15", stamped on the bracket is correct. I plan to send this, along with the evidence to the '70-'72 team leader for consideration.

See link for the recent (summer) thread on this subject:

https://www.forums.ncrs.org/showthread.php?t=71304&uid=8400

BTW: I've since corrected my VAC. I removed my aftermarket unit - now have a "437 15", and I am confident that I've corrected my NTFP issue.

[Edward J.]

Re: 72 Small Block Vaccum Advance #

Thanks For The Replys Guys ,Don I Read The Thread On Tdb Found It Interesting, Quite The Debate I Would Like To Know What Becomes Of This, When Finished.

I Plan On Having My Car Judged Next Year With The 437-15 Can On Dist.

[Joe L.]

Re: 72 Small Block Vaccum Advance #

I know the JM stated a no 437-16 canister no. but the one on my dist is a 437-15 which I beleive is orig. to car, could it be a possable there were other numbers. I seem to remember a discussion on this topic before, but looked could'nt find it. thanks Ed.

Ed----


Attached is a photo of an NOS GM #1973437 vacuum control I have. I don't know how old this one is, but the style packaging it was supplied in went out in the mid-70's. Note that the control is embossed 437 15

[Edward J.]

Re: 72 Small Block Vaccum Advance #

Joe, thanks for the photos, maybe this will help in the changes that need to be made in the JM.

[Jack H.]

Re: 72 Small Block Vaccum Advance #

There's an active thread on this in the '70-72 JG revision committee. I too submitted pix of an NOS service part along with mention of the original on my '71 SB (BOTH are stamped 437-15). Several fellow committee members challenged the service part as actual 'proof' since it wasn't a 'real McCoy' factory installed part...

Plus, the Chassis Service Manual for '71 lists distributors used and cites their vac advance silhouette. The table calls out 15-degrees for the base engine distributor. So, there's rather ample evidence that 437-16 is incorrect and 437-15 is right.

But, it's a matter of convincing enough committee members (and the NTL) that the current information cited in the JG is, in fact, incorrect... The process of making change is slow and that's good! Who wants to 'knee jerk' published information based on the observations of a few who've read this/seen that?

[William C.]

Re: 72 Small Block Vaccum Advance #

Don is correct the 16 (or 15) is the drgrees of advance provided by the vacuum can under full vacuum. The three digit number is the last three numbers of the GM part number.

[Don L.]

Re: 72 Small Block Vaccum Advance #

[quote=William Clupper (618);450300]Don is correct the 16 (or 15) is the drgrees of advance provided by the vacuum can under full vacuum. The three digit number is the last three numbers of the GM part number.[/quote]

Bill, we are seeing many (actually all so far) "437 15" parts. No "437 16" parts have come forward thus far. Are you aware of any such parts stamped with a 16 suffix?