1972 BB Distributor Vacuum Advance Canister

[Louis I.]

My question is this.... I have seen several "original" 454's, 70 thru 72, and noticed two different locations for the Vacuum Advance canister on the distributor. One location is behind the wire loom bracket, closest to the firewall. The other location is in front of the bracket, closer to the carb. Which location is correct???

The small blocks locate the canister closer to the firewall, where should the big blocks be?

Help!

Lou

[William C.]

Re: 1972 BB Distributor Vacuum Advance Canister

At least per the assy manual, only the smallblock uses the rear orientation. The 454 is clearly installed in the "standard" configuration. That also was the way my '72 BB was configured when I got it with 20000 miles on it.

[Louis I.]

Re: 1972 BB Distributor Vacuum Advance Canister

Thanks Bill for your post.... I think that makes two of us that have the orientation the same...

Lou

[Michael M.]

Re: 1972 BB Distributor Vacuum Advance Canister

On my 29K mile '72 BB Auto, which I don't think has ever been wrenched on, the can is in the "service bulletin" configuration ( closest to the firewall ).

Why would small blocks and big blocks be any different in the area ??? Seems to me the same problem ( kinked tach cable ) woul dbe solved with the same technique: "service bulletin" position.

[Louis I.]

Re: 1972 BB Distributor Vacuum Advance Canister

Mike, I think you are right.... that is why I asked this question... my tach cable is very tight and it makes more sense to have it closer to the firewall.... where do I get the service bullentin at? I obivously don't have that... I am debating on pulling the dist. and making the location change...

PS I have seen the difference between SB's and BB's. First hand and in GM documentation. I wonder when the service bullentin came out?? My car was built the first of March 72...it's a 4 sp if that makes any difference.

Anyone else out there with any info???

Lou

[Michael M.]

Re: 1972 BB Distributor Vacuum Advance Canister

I do not know the exact date of the service bulletin ... but it was Late '68, early '69 .. WAY before the '72 model year.

[Terry M.]

Re: 1972 BB Distributor Vacuum Advance Canister

I have printed the distributor orientation notice (for small blocks) twice in The Restorer -- the second time so that it would be sure to get in the CD. It is a notice from a 1968 issue of Chevrolet Service News. I'm not sure if that is the "Bulletin Mike is referring to, but it is all that I am aware of.

[Louis I.]

Re: 1972 BB Distributor Vacuum Advance Canister

Terry

Most Excellent, I have every one of the past Restorer issues... I will look for it there. This is way more than I had expected, your responses are greatly appreciated!

Lou

[Terry M.]

Re: 1972 BB Distributor Vacuum Advance Canister

Most recent printing was Volume 31, #1 -- Summer 2004 -- Page 17. Even I haven't been able to find the earlier printing, thus the reason for the reprint.

[Louis I.]

Re: 1972 BB Distributor Vacuum Advance Canister

Terry

I looked last night and found the recent volume.... my search went back to 1991 which is the earliest Restorer Mag. that I have.... couldn't find it back to then.

In the most recent volume (2004), as you said earlier, it is for the SB's. I noticed that the #1 spark position is also moved from the left of the distributor caps window to the right of the window... Is that the same on the BB's??? It would seem so as the length's of the wires are effected otherwise...???

Athough the bullentin states that all other V-8 engines are wired in the convention manner. How then should I wire my BB.

If anyone has this info or could tell me where the #1 wire is on the dist cap that would be marvolus!

If anyone has the service bullentin for the BB's or knows how to get a copy of it that would be great too...

Thanks
Lou

[Louis I.]

Re: 1972 BB Distributor Vacuum Advance Canister

Terry
Are you out there?? Did you see my post???

Help??

Thanks
Lou