4311 PB Booster

[John M.]

I have a 4311 booster that I took off my Feb 65 car, thinking it was for a 64 only. The julian number is 296 which would be late September 64, 5 months before the car's build date. I think this should be OK? I think I must have just read the judging manual which lists 7311, without thinking that a late 64 would work for early 65.
Agree?
Thanks
John McRae 30025 65 FI

[Michael G.]

Re: 4311 PB Booster

I have a 4311 booster that I took off my Feb 65 car, thinking it was for a 64 only. The julian number is 296 which would be late September 64, 5 months before the car's build date. I think this should be OK? I think I must have just read the judging manual which lists 7311, without thinking that a late 64 would work for early 65.
Agree?
Thanks
John McRae 30025 65 FI

I guess there's always potential for the wrong component to make it's way to the production line......however, why wouldn't the Julian date of 296 be for September 1963 applicable for a 1964 production? You're right ,7311 is correct for '65/66.

[John M.]

Re: 4311 PB Booster

Thanks Michael,
Why didn't I think of that? Maybe I did when I took it off.
Maybe I can trade it for a 7311...
I have the current GM repro on there now.
John

[Michael G.]

Re: 4311 PB Booster

Thanks Michael,
Why didn't I think of that? Maybe I did when I took it off.
Maybe I can trade it for a 7311...
I have the current GM repro on there now.
John

That's just my spin regarding your 4311 booster and the date. Why it would be on the car will be a question most likely not ever answered. I'm using a CSSB repro 7311 canister on my '66. Good functional replacement w/73ll stamped on front tab........see no reason to search out the real deal. Get's the job done.

[William C.]

Re: 4311 PB Booster

Any chance your car was originally a drum brake car?

[Michael H.]

Re: 4311 PB Booster

Any chance your car was originally a drum brake car?

Good point Bill. All 64 and 65 with drum brakes used a 4311 booster while 65 with disc used a 7011.

[Dan H.]

Re: 4311 PB Booster

FWIW that's the same Julian date code on my March 64 PB car. Must have made a bunch that day.

[William C.]

Re: 4311 PB Booster

Normal GM practice would be to rum a "minimum production quantity" related to required equipment setup time and expected volume requirement. For a low volume item, this might be one or two runs during a model year. If for a full size Chevrolet, likely several lines at once producing the same part, all day every day...

[John M.]

Re: 4311 PB Booster

I would say that the car was not an original drum brake car but it's not a question I would have asked the original owner. I will, just in case.
John