The Stovebolt Site Forums The Shop Area Engine Shop NPT Fitting Sizes on 216/235/261 Intake Manifolds

I am trying to put together a PCV kit and so far I have seen two different sizes of intake manifold Vacuum threads. I did not write them down! Does anyone know how many different sizes GM did for the 216/235/261 years?

The kit would include 4 feet of Vac hose, grommet, drilled out freeze plug, valve and fitting on the intake with barb. Then if you want the Deluxe kit, you would get a 3/8" stainless tube with proper fitting on the intake. I already know about the intake that has the offset and angled hole. I am hoping that is the only one GM did that way? Thanks!

In taking a walk out to the shop today, I found three different intake manifold sizes. They were 1/8" NPT, 3/8" NPT and 1/2" NPT. With Calipers they measure .405 inches for 1/8" NPT, .675 for 3/8" NPT and .840 for 1/2" NPT. Anyone know if there is more? The only 3/8" NPT ones I have seen are at that weird angle. Also, anyone know a good place to get Dorman fittings on the internet? I need 3/8" Inverted Flare (90 degrees) for all three sizes above.

I keep my bins stocked with these guys.

http://www.imperialsupplies.com/search/?SearchString=f+22+inverted+flare

And I buy a lot from these guys.

http://www.zoro.com/eaton-weatherhead-elbow-90-deg-38-in-inverted-flare-brass-402x6x6/i/G7565826/

Dorman has turned into Chinese junk.

The thing that I can't get a concise answer on is, I need a 3/8" NPT to 3/8" TUBE Inverted Flare. Some of them have it listed that way and what they really mean is 3/8" NPT to 5/8"-18 FLARE NUT (or do they?). I need 90 degree fittings in 1/8, 3/8 and 1/2 NPT with the same 5/8"-18 FLARE NUT fitting on one end. I can't find the 1/2" one anywhere.

I just thought it would be easier in the age of the internet to find these items. What would be the holy grail in this regard would be to find a 45 degree 3/8 NPT one. Been surfing and calling around all day!

Imperial has some pretty knowledgeable people on their staff. In fact I spoke with one of their reps just this morning. Imperial and Zoro are both wholly owned by WW Grainger. Grainger has the same stuff, but is quite a bit higher priced. You might give these guys a call. They kind of specialize in brake stuff.

http://www.inlinetube.com/

Brakes are about the only use for inverted flares these days. Parker-Weatherhead is now owned by Eaton and they don't have much interest in slow sellers.

I use nothing but Cunifer tubing on my old jalopies. I usually buy some in Europe, but when I run out, I buy some from these guys.
http://www.fedhillusa.com/

I have bought nuts from them. I have never asked about other fittings.

Of course its not as if I can't adapt the holes to fit something standard, but I am trying to avoid extra hardware. Looks right now that I need to put a 3/8" adapter bushing in the kit if they have a 1/2" port. Its all in the research isn't it? Thanks Ken!

For your info. If someone has a Edelbrock intake it uses a 1/2" npt

Thanks wolf! Good to know.