Carb Sizing/vacuum or Mechanical

[F-BIRD'88]

A custom built 750 HP carb will show a bit more top end power. Ya it won't have the right origional holley carb colour. When the air cleaner is on nobody can see it.
There is perf in using the right air cleaner also.
The old GM "L71, Z/28, LT-1 air cleaner works best.
You can upgrade any used 700,750,800 DP carb to 750 HP status with the Holley/Proform HP carb body kit.

You might try a carb spacer under the carb.
Unless you drag race it how will you know?
Yiu only need to rev it as much as it needs to rev up on shifts. You'll see with track testing excessive rpm slows the ¼ et slip. 6000-6200 is plenty for that hyd roller.

[F-BIRD'88]

Car needs some 4.30 gearz and 8.5/26 Mickey Thompsons and traction bars. Then go test/tune it for best carb perf.

[Horder]

lol...well it has old school traction bars. Not sure I could deal with the 4.30 gears though.

[rgalajda]

Car needs some 4.30 gearz and 8.5/26 Mickey Thompsons and traction bars. Then go test/tune it for best carb perf.

You sure know how to wreck a good street car

[Horder]

A custom built 750 HP carb will show a bit more top end power. Ya it won't have the right origional holley carb colour. When the air cleaner is on nobody can see it.
There is perf in using the right air cleaner also.
The old GM "L71, Z/28, LT-1 air cleaner works best.
You can upgrade any used 700,750,800 DP carb to 750 HP status with the Holley/Proform HP carb body kit.

You might try a carb spacer under the carb.
Unless you drag race it how will you know?
Yiu only need to rev it as much as it needs to rev up on shifts. You'll see with track testing excessive rpm slows the ¼ et slip. 6000-6200 is plenty for that hyd roller.

You believe the drop base on the Z28/LT1 air cleaner is better than a flat base? I presently use an L79 dual snorkel air cleaner with its flat base. On the back side where no one can see I have opened up the vertical part of the lid so it can draw air like an open element as well as through the snorkels. The Z28 drop base would work on my lid. If it flows better it also gives me more room to play with spacers...

[F-BIRD'88]

The only time this gm muscle car 14" drop base air cleaner will not work well is if with a aftermarket holley carb that has the taller choke horn.
with these I reconebd removing that choke horn on these specific holley carbs.
The OEM holleys had a different shorter choke horn and down leg boosters. The other carbs Eddy, carter ,qjet are not so effected. The whole air cleaner can be raised up a bit with a carb to air cleaner spacer if desired.
I believe its more to do with air flow quality and directivity VS just air flow volume. GM did their home work on this one. You can buy the base alone now too. The shape contour of the lid plays a roll with the base contour shape to get the desired air flow pattern and quality overall. What goes on at 60 mph or 100 mph is not the same as what goes on when the car or engine is stationary during testing (dyno testing)
we don't drive dynos at road speed nor simulate that air flow effect on the carb during dyno testing.

This is the lowest sitting best contoured drop base air cleaner I have tested on various cars.
It out performes the typical aftermarket drop base air cleaners. beyond sitting lower height.

[F-BIRD'88]

If you are crafty you can also use this air cleaner as a start point to creating a enclosed ducted "ram air" style air cleaner.. Might find parts and components from www.RAMAIR.com. web site usefull.

[skinny z]

If you are crafty you can also use this air cleaner as a start point to creating a enclosed ducted "ram air" style air cleaner.. Might find parts and components from www.RAMAIR.com. web site usefull.

Having been in touch with the Ram Air Box guys, this too is still on my radar. At one point it looked like they had gone tits up however a few months back they responded to an email inquiry.

https://www.ramairbox.com/models.html

[rgalajda]

I have restored/rebuilt some of the factory holley carbs that used this air breather factory OEM.
List 4801 1971 LT1 / 4803 1971 LS6 / 4346 1969 396/375hp Chevelle.
I have two of them sitting on the shelf. All of these carbs have the same choke horn height as the aftermarket Holley carbs such as the 3310-1/2/3 , 1850, 4779, including a Quick Fuel carb sitting on my shelf.
The difference being is the height of the vent tubes.
This air breather requires a short / angle cut vent tube. Also the tabs ( arrow in picture ) need to be modified for most aftermarket carbs. Holley carbs with the cast in vent tubes require some modification
I use this air breather personally. You can see in the picture how this air breather is contoured around the fuel bowls .

AIR-190K-2T.jpg

AIR-190K-2T.jpg

s-l1600.jpg

[Horder]

I just ordered the OER copy of the factory Gm/Z28 air cleaner. I should have it next week.

I tried reducing the primary squirter to a 28. It did not like it. It stumbled for a blip and then recovered. Went back to a 31 and Boom. All good again. Too muggy here right now to do plug checks for jetting but my initial thoughts are that it wants a little less primary jet. I think its gonna like a 70.

Love the 3310-1 so far.

[Horder]

Well ive got a bunch of miles on the 3310-1. Its a very nice Carbeurator. It idles very well on my aluminum headed, 10.3:1, roller, 327. I ended up with 70/76 jetting. 6.5/6.5 power valves and a 31 squirter. Really likes only 1 turn out on the idles screws. Plugs look great. Long yellow secondary spring works best is seems. Secondary all in by 5000 RPM. No bogging anywhere.

I have swapped the 4776 600 cfm double pumper back on a couple times. There are some differences for sure

The 4776 pulls harder from 2000-4500 RPM even with the secondaries smashed wide open. Tapping the throttle causes the little car to just jump. The 3310 is not bad here, just not as good…at least with the tuning I have done.

Where the 3310 shines is just above 4000 RPM. The revs climb faster to 6200 in each gear. The engine likes the added carb size. I guess the 600 is a bit small.

The biggest surprise is the drop base Z28/LT1 air cleaner I purchased. It does not perform as well as my L79 dual snorkel. i am not sure if that is due to the fact that I run a choke tower and the clearance to the lid isn't great enough???

[skinny z]

. i am not sure if that is due to the fact that I run a choke tower and the clearance to the lid isn't great enough???

How close?

[Horder]

Honestly I haven't measured. I will do that early next week as I am away for the weekend. The extra hood clearance is very nice for experimenting with spacers for sure.

[Tom68]

Where the 3310 shines is just above 4000 RPM. The revs climb faster to 6200 in each gear. The engine likes the added carb size. I guess the 600 is a bit small.

[Horder]

Tom68 said early on that a 600 was bit small for a good 327. I believe he is right.

I said I thought a 650 Double Pumper was the right carb for this car/engine. I think I could be right as well

The difference is….mine was basically a guess. Lol