61 Carb Fitting for Vacuum Line to PG Trans

[Richard C.]

I have a 61' with single carb (230 HP) and Powerglide Transmission. I am missing the elbow fitting (#3782587) that goes at the rear base of the carb that supplys vacuum to the modulator valve on the cast iron powerglide transmission. I was wondering if someone could provide me with a picture of what I need to be looking for.

From the AIM (section 313, sheet 7) it shows that this fitting can be used on both the single and dual carb setup with a PG trans. From what I have found out so far it appears that this fitting may have only been used on a 61' with the PG trans. The elbow fitting has a 1/4" male pipe thread that goes into the carb and that other end has inverted thread for a steel line with a 3/16" fitting. If someone assist me with this Iwould greatly appreciate it.

Thanks,
Richard

[Peter V.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Richard,

I have a '61 230 HP PG car with the fitting you described. I'll try to take a picture tonight and post it tomorrow (if I can figure out how to post a picture!).

[Jack H.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Check out C-Central's catalog, their PN 351066, Rear Carb & FI Vacuum Take Off Fitting, $12.50...

[Clem Z.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

I have a 61' with single carb (230 HP) and Powerglide Transmission. I am missing the elbow fitting (#3782587) that goes at the rear base of the carb that supplys vacuum to the modulator valve on the cast iron powerglide transmission. I was wondering if someone could provide me with a picture of what I need to be looking for.

From the AIM (section 313, sheet 7) it shows that this fitting can be used on both the single and dual carb setup with a PG trans. From what I have found out so far it appears that this fitting may have only been used on a 61' with the PG trans. The elbow fitting has a 1/4" male pipe thread that goes into the carb and that other end has inverted thread for a steel line with a 3/16" fitting. If someone assist me with this Iwould greatly appreciate it.

Thanks,
Richard

check out the weatherhead fitting catalog at your auto parts as most likely it will be there

[Las K.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Peter, is it a brass fitting?

[Peter V.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Las - mine appears to be brass. I also have the crankcase ventilation option. The fitting appears to be attached to the larger Crankcase fitting.
This site won't upload the pic and I can't figure out how to shrink it to fit.
Richard - email me at petervangsness@hotmail.com and I'll reply with two pictures attached.

[Richard C.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Thanks, but that fittings is used for cars without an automatic transmission. The vacuum line on my car is a steel line with a 3/16" fitting. The fitting you mentioned is for a rubber line. Paragon also has that same fitting and they describe the fitting is not for a automatic trans.

[Richard C.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Thanks, weatherhead does not have the fitting in their catalog. It must have be a special fitting made for GM.

[Las K.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Richard, Something just doesn't seem right. The powerglide receives vacuum from the hollow stud at the rear left side of the carb whereas the washer hose is connected to the fitting at the back of the carb. If we're finding something new, than a lot of us have been chasing the wrong connection. I have studied the AIM, spoken to the NCRS judges, and all is inconclusive.

I'll get the photos from Peter and post them for all to see. I have been chasing that brass fitting which he describes for the past 3 years and have had no luck in finding one.

Let continue the discussion.

[Jack H.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Hum, the vac 'plumbing' gets pretty complex depending on the EXACT configuration of the car. The hollow stud provides vac to the distributor advance and the WSW reservoir.

When you add the PG automatic, the rear of the carb is tapped for vac to supply the AT via the 3782587 elbow that was originally mentioned. BUT, if option 242 is added (PCV), things get REAL complicated REAL fast!

A 444148 tee fitting services the rear of the carb to accommodate the transmission AND the PCV valve. This fitting also shows up on FI cars equipped with the PCV option. Plus, if the configuration is AT, dual 4-Bbl and PCV, there's major 'surgery' called out for the carb to tranny vacuum tube...

Few '61 cars were PCV equipped and the original post didn't mention that option along with its complicating factors. This part (3782587, Elbow) HAS to be out there...

[Jack H.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Although there are some here who cringe at the mention of Chicago Corvette, I dove through their catalog. They list two vacuum fittings for WCFB applications. One is our 'friend' the hollow stud the other has a different catalog number.

Their Cat No. A3714, is described as applicable to '55-62 cars. The physical text reads: "Fitting -- vacuum, for auto transmission, (on the carb)."

That sounds to me like the bugger in our gun sites. But, one could always call and confirm that their A3714 = GM 3782587 before laying down the whooping $10 (catalog is old, confirm current price) they're asking...

Whatever one may personally feel about Chicago Corvette, Al Fierke DID get his start in the business by specializing in carbs. In my personal interactions, he's NEVER lied to me when I phrased my question CRYSTAL clear...

Last, remember in '61 there were TWO versions of vacuum take-off fitting for the rear of the carb: (1) one for standard cars with AT (3782587, Elbow), and (2) another for that rare PCV equipped car (444148, Tee). So, I'd be very precise in phrasing the question about what their catalog number A3714 actually is...

[Peter V.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

I sent Richard the pics from my car, and hopefully he'll be able to post them here. As previously mentioned, I have the rare RPO 242, so my fitting is at the back of the brass PVC fitting.

[Peter V.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

I meant to type "PCV", not "PVC".

[Richard C.]

Re: 61 Carb Fitting for Vacuum Line to PG Trans

Peter- From the pictures you provided (hopefully 1 is attached here) the fitting that I need will be different from what yours is because of your RPO 242 option. See Noland's Tech Guide pages 358 & 359. Yours seems to be somewhat different that what is shown in those drawings. Thanks for sharing your pictures.

Las- I believe the set-up you are describing is for the 58'-60'(?). See Noland's Tech Guide page 267. For the 61', I believe it will be different. See Noland's Tech Guide page 363, top right drawing, I believe the set up that I need is shown in the lower right section. For the 62', It will be different as well because it used an aluminum PG transmission.

Jack- Thanks for your input. I will check w/ Chicago about their fitting A3714. I question wheither it will be correct since it covers 55'-62' and it appears there were several changes throughout those years.

If anyone can add to this thread and help resolve this or provide a picture I would greatly appreciate it. I hope that I can locate the fitting soon because my goal is to have my car completed by the end of this year.

Thanks to all,
Richard Crowley