66 327/350 distributor vacuum can

[Paul K.]

the stock distributor vacuum can for a 327/350(MS 236 16), does this relate to a B 26 or B 22?

Paul Kemetson 37278

[Jack H.]

Re: 66 327/350 distributor vacuum can

I'm going to say neither. Here is some info I captured from one of Duke's posts from a few years ago:

B22 (201 15): 15", base engines or opt. engines with base engine cam and manual trans

B26 (355 16): 12", base/base cam opt. engines w/auto trans, all big blocks w/manual trans, L-79, L-46, L-82 w/ manual trans

B28 (236 16): 8", all OE SB w/mechanical lifter cams, L-82 automatic

[Leif A.]

Re: 66 327/350 distributor vacuum can

The stock can, if memory serves, was closer to a B28 but that can was much too aggressive (all in at about 8" hg). Put a "T" in your vacuum line between your vacuum canister and the carb and get an accurate reading with idle at 700RPM in neutral...should be around 14-15" hg. The B26 can is the recommended can for a typical L79...it's all in at around 12" hg. They can be had from Rock Auto.

[Donald L.]

Re: 66 327/350 distributor vacuum can

MS 236-16 VAC relates more to a B28. Both are fully deployed @8 Inches HG. B26 & B22 are less aggressive.

[Joe L.]

Re: 66 327/350 distributor vacuum can

the stock distributor vacuum can for a 327/350(MS 236 16), does this relate to a B 26 or B 22?

Paul Kemetson 37278

Paul------


The GM #1116236 vacuum control is equivalent to the "B28".

[Duke W.]

Re: 66 327/350 distributor vacuum can

The original 8" MS 236 16 VAC (B28 replacement) is more aggressive than necessary while the centrifugal curve was the least aggressive ever in a small block... a very weird situation.

Typical L-79 idle behavior (assuming a OE equivalent cam, but never assume anything and measure yourself) is 14-15" @ 750 so you only need a 12" VAC to meet the Two-Inch Rule, which would be the current 12" B26.

You can search here or on the CF forum for a writeup I did - L-79 blueprint overhaul - on how to dial in a L-79 distributor. The only change is that it appears that the black springs in the Mr. Gasket 928G spring set are the lightest followed by silver and gold. There is also more information in my tuning seminar that is on the Web, search Duke Williams tuning Corvettes.

Duke