Vacuum Fitting

[Seon]

The recently installed 327 in the wife's Impala has the stock intake manifold with a Carter carb that has only has two vacuum fitting. One in the rear where I installed a T-fitting and connected the brake booster and a PVC55 hose. The other is small 1/8” vacuum fitting towards the front of the carb where the distributor hose is connected.
The problem I have is there's no other vacuum fitting to connect the transmission modulator. The transmission rebuild shop said I need a dedicated line for the modulator.
Question is, can I tap into the back T-fitting where the booster and PVC55 hose are connected for the transmission modulator?

If not, will this Trans-dapt 2584 Phenolic Carburetor Spacer work that has a fitting that I can use?
https://www.mechanicsurplus.com/products/90145070

 

[Carl 1962]

One of the carburetor mounting studs on my original 327 was hollow which provided vacuum for the transmission modulator. See if you can find one of these hollow studs. I assume that the Carter used the same system as the Rochester 4GC.


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[DonSSDD]

Either of the rear carb studs were hollow on many Chevy carbs, I used one on the 59, 62, and 63. Show Cars had them, also available from vette vendors.

 

[Seon]

I'll check those stud holes and hopefully they provide vacuum. If so, it's easy enough to chuck a 1/4" longer stud on my lathe and drill a hole. Thanks guys.

Update: I ran across this diagram that depicts using a 4 way brass fitting that connects booster, PCV hose and trans modulator. Looks interesting. I currently have a 3 way fitting and easy enough to swap it to a 4 way.

 

[1958 delivery]

I've had issues with the booster and PCV tee'd together. PCV was too large a leak and caused brake pedal (booster) to pulsate with much lack of braking ability. Anxious to hear your results
As far as modulator, why not tee it with distributor?

 

[Seon]

It was my understanding that the distributor hose should be dedicated to one nipple.

 

[1958 delivery]

It was my understanding that the distributor hose should be dedicated to one nipple.

There is no "flow" associated with either, I can't see why it doesn't work. If memory serves me it was done that way on many OEM applications. I'm pretty some of my early Corvettes had a multi prong mani fitting and those were hooked there

 

[1958 delivery]

Pretty common used for brakes, trans and distributor. PCV seems to usually off the rear carb fitting. Never seen PCV and brakes together

 

[Seon]

Reading previous years posts on Chevytalk appears you're correct Mike. Tee-ing off the distributor line to the carb is/was a standard practice. Oh btw I checked the stud holes on a spare intake manifold that was on the self and the passenger rear bolt holes does provide a vacuum where the other three does not.
Above replies certainly provided several approach and has helped answered my modulator question.
I think the easiest method is to Tee off the distributor line.
Thx all.

 

[Seon]

Just a follow up that I Teed off the distributor hose and transmission shifted as it should.

 

[pvs409]

Here is my 62 Impala 327/300 HP with a 700 R4 overdrive and stock distributor with vacccum advance, Power brakes, PVC off back of carb
the hose to the carb stud is for a aftermarket cruise control.