6 Cyl Brake Booster Question

[Sgt.Booya]

Hi, I need some help from the I6 guys or anyone in the know. I'm just about to start my power brake conversion. I'm using this FAQ as my guide,(http://67-72chevytrucks.com/vboard/s...d.php?t=163387) however, I have a I6, 250 in my truck. The last step in this process is hooking into the intake for vaccum. On the V8 in his (farside847's) application it looked like he used a spare plug in the intake with a plumbing fitting. See picture below:


This can't be done exactly as shown in the example on the I6 as the intake is different. Here is a picture of my intake:


I'm thinking if I take this fitting out (see arrow in picture) and replace it with some sort of plumbing "T" fitting and run both systems off the same supply, it might just do the job. The existing vaccum line on there now runs down to the tranny. Not sure if this would work fine or if it would adversely effect the operation of both

Has anybody done this conversion on an I6?

Does anyone have pictures of how a I6 power brake system is set up from the factory?

Would my solution work?

[shelby987]

I am gonna assume you have an automatic then. I used that same port for my conversion, worked fine. Logically speaking (and please someone else chime in if I am wrong), but from the distributor vac. advance, to the brake booster, they are all working off of the engine vaccum, just different ports, vaccum doesn't decrease if other systems are using it. I would think you would be fine just putting a t-fitting in there.
I guess my reasoning is, if you had a manual and manual breaks, your engine would still have the same pull/vaccum as a truck with an automatic and power brakes.
good luck, and remember you will either need a smaller air cleaner, or a specific pb. air cleaner when you are done, your old one won't work. (get a 5" cleaner, you can use it if you swap to a 4bbl down the road.)

[Sgt.Booya]

Thanks shelby987. Yes, I have an automatic transmission. Looking at it today, I was wondering if the air cleaner was going to fit or not. Thanks, that will save me a trip to the parts store. Since you used the same port on your conversion and its working fine, that's all I needed to hear.

Still curious though, any of you I6'ers have power brakes from the factory? Be interested to see how GM provided vacuum to the power booster. Maybe there is a factory part I could order? (Just trying to keep my getto fabs to a minimum....)

[Rod]

This pic I had saved looks correct. With a PB booster you need this style air breather assembly...stock 6 cyl ones wont fit with the booster there. This pic in a standard trans, but no matter.

[ChevyMex]

Is that an oil based air cleaner?

[ChevyMex]

Here is my 68, 292.

[TugOwar]

Not to hijack the thread but I see GOLD on that firewall ChevyMex, could it be you have a 50th anniversary edition? Did any 50ths go to Mexico? Just curious.

[Sgt.Booya]

Thanks for the pics guys.

The one & only port on the intake manifold is definitely the way to go. I'll figure something out there with a plumbing fitting.

Geez Rod, that air breather is really something. I'll never be able find (or make?) anything like that. I'll maybe try and go with something like want ChevyMex has.

I'm still waiting on a power brake check valve to come in the mail and I'll let you know how I made out.

[Americanrider]

Try junkyard hunting for that air cleaner on early chevy Vans w/ I-6's. They are also good parts sources for 6Cly Power Steering mounts and door arm rests.

[ChevyMex]

Tugowar, nop i wish. The truck original color was blue and white, i have painted the truck 3 times since my father gave it to me. At this time we are working to make it green olive and white. I am just learning that many of the good stuff of these trucks were not offered in Mexico, even the bed is different.
Hey, that air cleanner from Rod is oil based or use a cardboard filter?

[Rod]

ChevyMe..the pic I posted uses a paper type filter..normal style.

Check your PM Sgt.Booya

[shelby987]

I have seen a couple of those air cleaners for sale on the parts board here actually......if you really want, it would be worth a wtb thread.

With respect to keeping the "ghetto fab" to a minimum, a T fitting off of almost any car in the junk yard, and piggy-back off of a vaccum fitting underneath the air cleaner toward the firewall....maybe for the vac. advance?, then you can use a single fitting to run the booster.....I actually seem to remember my 1bbl having an extra fitting on it right before I pulled it...hmmmm. (I remember because I blew the rubber stopper, and immediately lost my PB right after install)

Just a suggestion.....good luck, and the modification is well worth it.