Another VAC question

[John L.]

Sirs
I recently had some drivability problems with my '65 250hp/327 that I traced down to the VAC. It turned out to be the steel vac line vibrated loose from the front of the carb. BUT before I discovered this I had already pulled the VAC, which was a B9. I got this B9 from one of the Corvette suppliers 10 years ago, which said it was correct but I never felt it was best for this engine.
My question is this: When I pulled the B9 it had a bushing on the control rod. I replaced the VAC with the original without the bushing (its a MS 201 - 15) . DID THE CAR come with the bushing?......can't find any info in my references regarding this VAC other than it was introduced MAR 1 '65

[Duke W.]

Re: Another VAC question

The OE VAC was an oldball on your '65 327/250. It had 20 or more degrees, which was too much. There was a TSB written on the subject, which I am sure I have posted here, but can't upload it now as I don't have access to my files.

The ideal spark advance map would be 30 centrifugal all in at 2500-3500. 6-10 initial and a 15" B22 VAC if a manual and a 12" B26 if Powerglide.

Duke

[John L.]

Re: Another VAC question

Sirs:
Thanks Duke..... I just ordered a B22...... It wasn't easy to find because the calibration code i.e. B22 or B9 or B1 etc. are stamped on the arm and the cross references seem to be a secret.
If someone wants to order a B22, the part no.s are V235 for BWD (engine management technology) and VC171 for SMP (standard motor products) and is cataloged for 71/72 Corvette 350.
Most suppliers list B9 or B1 for 65 all 327s except FI......The B9 is close to correct,.. but no cigar as if probably violates to 2" rule, at least on my motor.