396 distributor / vacuum advance

[Michael H.]

Re: 396 distributor / vacuum advance

I have worked on dozens of #093 distributors and have found all early units (65 396CI) had a #355 vac, which agrees with my copies of original design blueprints (best source for OEM P/Ns & data in my opinion), and Delco Specs. I have found later (66 427CI) original units all had #360. The design blueprint date for the #360 vac is 5-11-65, which is prior to the end of the 65 run; however, in my experience, I have not seen a #360 installed in a #093 earlier than late August. Although the normal delay; design date to seeing a design change on the line is usually about a month, in this case I have not experienced this change earlier than late August. So, this delay could be due to the use of what was in inventory (#355), or to coincide with the model/engine change; or, simply my lack of sufficient sampling in the 50+ units I have worked on (have 5 in inventory). The design blueprints do not indicate anything re: #163, therefore, I suspect it to be a service replacement, as indicated in the Service Bulletin Wayne posted. #201 could also be indicated as a Service Replacement, as it was used on HiPo BB motors from 67-71. The B26 is an aftermarket Echlin piece.
Michael Z

Michael,

My Nov 65 built 66 L72 car had a 360 vac adv unit when I bought it in 1984. I replaced it with a new 360 unit at that time.