72 LS-5 Distributor question

[Mike E.]

I'm helping with a relatively undisturbed 72 LS-5 4-speed coupe. This was owned since the mid-70's by one brother who sold it to his other brother. They know absolutely nothing about numbers. The only non-original component I've found is the starter.
The distributor is the correct 2051, but the vacuum can is a 436 20. The JG indicates that it should be a 436 16.
Any thoughts about why the difference? Is the JG incorrect, or is the vacuum can incorrect?
Thanks!

[Jack H.]

Re: 72 LS-5 Distributor question

Might be a game of specsmanship, Rev Mike... My copy of the '71 Chassis Service Manual lists the '2051 distributor for that year as well (rear Specifications section). And, when it comes to describing the vac advance, the spec is 0-degrees at 8" Hg and 20-degrees at 17" Hg.

Those of us who contribute to the JG book have a similar discussion going about what's right/factory original for the '71 base SB distributor's vac advance (what's stamped on the vac can vs. what's currently said to be factory original)...

[William C.]

Re: 72 LS-5 Distributor question

Mike, the Delco Remy factory specs for the distributor in question call for the '436 vacuum can. All the team leaders should have this information available to them, I know for sure Roy has ti. If you need a copy, send me a PM and I'll send you the files I scanned.

[Edward J.]

Re: 72 LS-5 Distributor question

Jack, if the manuel says 17" is 20 degeres would that not make the number on the vaccum can correct?