If you're not familiar with it, this is a 2"-drop 14" air cleaner base that was used on the late '60s & early '70s Corvettes (and?) because of their limited hood clearance. I've seen some folks on other boards say it's still a good option for anyone who needs a dropped-base air cleaner, but have no first- (or even second-) hand experience with it. There are reproduction bases available, so it's not a problem to find one. Any feedback here?

They are a good drop and clear most obstacles on the engine.
I use to run one back when I ran a LT1.
Now I run a GM alternator on a Mopar for the amperage. Go figure.

For comparison, this is a generic pic of the style of drop-base that K&N and Moroso offer, and which I've been using for years. Depending on the brand & part #, they have from about 1" to 1-1/4" drop, so not nearly as much as that L88 base.

This design isn't as "form fitted" around the carb / choke / linkage / whatever as the GM part. It makes me wonder which works better in the real world when equipped with the appropriate filter height that provides the same amount of clearance between the top of the carb and the underside of the air cleaner lid.

I was interested in this but I need to get rid of the choke horn effecting the pri side the most 1st.

Looks good.

More than fitment, I'd be concerned w/flow path but maybe it has little affect OR, a lot which makes a WB readout w/different changes fun and info is gained both good and bad..........

I use an aftermarket version on my 1050cfm 4150 style Holley.
Small supercharger under it.
Runs the same with or without.

Here's a cross-section of the Braswell air cleaner that's a 14.25" base and 15.25" top IIRC) so that the filter tilts away from the walls of the base. It also requires a spacer to raise the base above the fuel-level adjustment screws. Not sure if this is one for their 4825 or 4760 carbs. Also, no data on their web site as to how much the air cleaner sits above the carb flange, though... looks pretty tall for a drop-base setup.

Notice the taper on the lid to channel air down it's throat..........

The crankcase vent tube on the passenger side rear of original gm bases interferes with a double pumper rear accelerator pump mechanism, I believe they addressed this on the repops(?). Also I don't think it will sit down on a generic chrome "dual line" fuel line, you may have to run the factory GM style "Y" block and 5/16 fuel lines (fuel block to bowls), although you may be able to bend a chrome one down enough to clear.

I think the big issue will be how it sits down over the accelerator lever rod that sticks out toward the driver side fender, you may be able to eliminate it on a std trans car, but an automatic.....???
Just a little FYI from a former bowtie fan.

jess

The reproduction I was looking at said "no breather tube on base". Here's the current fuel line setup, but no pictures handy showing the throttle linkage side. The car has a manual valve body auto, so there's no kickdown linkage to get in the way.

Among other things...

Brad
Who made or where did you get the bracket that holds the pressure regulator. Nice looking piece.

Jeg's; they offer them for a variety of brands of regulators.

I run an Allstar air cleaner.

http://allstarperformance.carshopinc.com/product_info.php/products_id/4315/26098

I dont like drop base air clearers.. they
change the direction of the air(restriction)
but if you have to use them then you have no
choice... just remember ALL air cleaners are
a restriction.. I did a few years testing air
cleaners for Chrysler

I was running a spectre 3 inch drop base for a long time on my car. I went to a Moroso flat bottom to install a fuel pressure regulator mounted on the bracket like you have. I didnt actually install the regulator yet, just made sure I had room and its been sitting on the shelf since haha.

Anyway, my old one put the lid pretty close to the bowl vents/choke tower. I did notice a difference in how much I had to slip the clutch. Also it was pretty hard to really smoke the slicks when I dumped the clutch before, itd spin them and go. A 3k dump just ROASTS them now. It doesnt feel like I picked up crazy horsepower but the car is more responsive.

Also, with the flat bottom I could only fit a 2 inch filter, but the lid is still about an inch higher than it used to be. Ordered an RO23 scoop so I can run a taller filter, but wont be in for a few weeks.

Yes I've used one. As said, you have to remove breather tube for use with a DP carb. GM dealers can order this part#.

Thanks for all the replies; I have a couple of new ideas on what direction I want to go with my air cleaner setup now.

I did back to back testing at the track this summer. A K&N filtered drop base aircleaner vs. no aircleaner at all. Identical 11.41 times and mph with and without.