I am trying to find the carburetor pad height for this manifold. Can anyone help

 

Hi. I have this intake. How would I measure it? Does it need to be installed in the car to get the measurement? Mine's on the bench.

 

Like such:

 

Okay 1965 intake part # 3844461.

I measured the intake like the above diagram a measurement "A" at the front of the intake is 3 3/4" and "B" measurement 4 5/8" on the rear.

3 3/4 + 4 5/8 = 8 3/8
8.375 ÷2= 4.1875"
4.1875" pad height

Did I get that right?
How do you use the pad height to determine if the hood will fit?

 

Using your measurements and math the pad height would be 4.1875". What carburetor and air cleaner are you wanting to use? This intake is not going to be a problem as it was the stock intake for '65 L79 small blocks. Clearance issue (if any) is going to be determined by the carb and air cleaner choice.

 

I have a 670 Holley Avenger vacuum secondary carb. With a 3-inch drop air cleaner from a 69 396 Camaro. The PCV block vent fitting was moved to the driver side. The trouble is this air cleaner rubs. takes the paint off the hood at the 2 o'clock position. I think it must rub when I rev It Up. I have been running a 2 3/4" filter for a little extra clearance. But that puts the lid very close to the carburetor and I can no longer get the 2 3/4" size. So I am now looking for options as well. Do you think my carburetor would be taller then the stock carburetor? Or maybe my service replacement motor mounts sit the motor a little higher?

 

My 670 Holley is 3 1/4" from the base at the intake to the lip the air cleaner sits on. Any idea what a stock carb height would be? I believe in 65 it was a 2818-1 carb.

 

Attached is a summary I put together a while back that compares the height of some GM intakes to several Edelbrock intakes.

When I measured the L79 intake, I calculated 4.19," which is consistent with what others have reported.

There should be no problem fitting the L79 intake under a C2 hood. GM used that intake as a production part on the C2, and they certainly left enough hood clearance to account for normal production tolerances.

When I wanted to install the Z28 intake (which is 1/2" taller) on my '67, I made careful measurements and found that there was about 3/8" additional room above the L79 intake. Others who have put the Z28 intake on a C2 have reported that on some C2s it fits and on other C2s it interferes slightly. The relationship between the frame and the body is slightly different on each car.

To get the Z28 intake to fit on my '67, I added four shims to every body mount, which raised the body by 1/4". Now the Z28 intake fits fine under the hood.

I'm surprised that the L79 intake is giving you trouble with hood clearance, since the available clearance *should* be about 3/8" to 1/2". If the L79 intake is hitting the hood, there must be something unusual about the setup.

The first thing I would check is to test-fit an actual L79 air cleaner, and also confirm that the carb is the same height as the original. If those check out okay then you may want to see if there is something unusual about the motor mounts, or possibly something unusual about previous repairs to the front end fiberglass.

 

I have a repo 350 HP air cleaner. But it does not fit. It hits the float adjustment screws on this carburetor. I may go to a stock style carburetor and air filter. Would you know the height of the stock carburetor 2818 / 1850 style Holley. Mine is 3 1/4" from base to the lip for the air cleaner.

Dave

 

I have heard of the problem with the air cleaner base hitting the float adjustment screws, but I think that was fixed for the '66-'67 Corvette air cleaner. Do you know what year your repro air cleaner base is for?

I have a Holley Street Avenger carb (770 CFM, I think), and my stock '67 air cleaner base fits fine. I will take a closer look at this when I'm in the garage tomorrow. I will also measure the height of the Street Avenger carb and the original 3810 carb, but I'm pretty sure I checked that some time ago, and the heights were identical.

 

I thought they would be the same height. But I've never measured. My repo air cleaner is a 65.

 

Dave, I'm using a BG Demon carb on a Tarantula manifold and had some clearance issues getting the air cleaner base to sit nice on the carb.



I marked the areas on the air cleaner base that needed additional clearance and using a "Panelbeater Sandbag", with the base upside down, created some additional clearance in the 12 & 6 o'clock positions for the float bowl adjustment screws.



It didn't take a lot of massaging and now the base sits correctly on the carb. My air cleaner was picked up at Carlisle for a '66 small block.

Good luck... GUSTO

 

I think my 3" drop air cleaner base sits flush with the carb. I can recheck it. But the 65 repo base is not even close. I think I would have to cut holes in the base to clear float adjustment screws. I'll pull the repo base out and try it again. It has been a few years since I last tried it.

 

Okay, I made some measurements and took a photo of my original '67 air cleaner base plate. The two areas circled in yellow are the clearance provisions for the float bowl adjustment screws. I think this feature was added when GM switched to the Holley carb in 1966.

For the Holley Street Avenger carb that I have on my car, there is almost 1/4" clearance between the float adjustment screw and the air cleaner base plate.

Regarding the carburetor height, both the original 3810 and the Street Avenger measure about 3.25" from the intake mounting surface to the shoulder that the base plate rests on.

BTW, PM me if you want an unused repro '67 baseplate. I bought one with the intention of modifying it to help me fit the Z28 on my car, but I ended up solving the problem by adding shims to lift the body.

 

Yes I thought the Holley's were all the same height 3 1/4". Here is a picture of my 3" drop base, it looks the same as yours. And fits flush to the carb. And a pic of the 65 repo base which sits up on the float screws.
Sits up about 3/8"
Hitting float adjustment screws.

 

65 repo base
65 repo base

 

Braden. Sorry for stealing your thread. Hopefully some of this info is helping you as well.

Dave

 

Just Curious....Does anyone know why the top of the intake (where the carb mounts) has a rectangle on the passenger side and two round holes on the driver's side?
Very unique design. There must be a reason but I have never seen an explanation.

 

Does anyone know why this intake manifold design (where the carb mounts) incorporates a rectangle on the passenger side and two round holes on the driver's side? Very unique design.