believe the only offset pot is used with '57 Deluxe Heater only.

 

56 dual quad air cleaners have fixed rotation pots. The stacks on the carbs are about 1 inch higher than 57's

Early 57's did not have an off set pot on the RH side until about December of 56.

The spacing between the stacks on Caddy air cleaners are several inches wider. The Caddy air cleaner points is to the front. Chevy turned it around 180 for rear clearance.

Packard's used the same air cleaner body but the internal air tubes are different, and the carb spacing is as well.

A few of these were also used on come Mopar engines.

Mikey

 

3. None, the only are when you take the pods off and look at the internals of the pods they're SLIGHTLY different. If you have to ask this question, 99.99999% of people will never detect it.

4. The fiberglass versions are junk. Don't ever get one, and when trying to buy one always ask to make sure it's not fiberglass.

5. No. Unless you look extremely close at the crimp, even then 99.999999% of people will never detect it.

The steel reproduction is a work of art and done by someone who truly cared about the historical preservation of the part. I'm an anal sun of a gun and would/will gladly buy another to do another car.

 

---------------------------------------------------- If you have to ask this question, 99.99999% of people will never detect it.
--------------------------------------------------------------

And I absolutely, totally 100% agree!
Think about it, just how many people on this planet are batwing experts???????????
Again, I feel the new repo batwing is as good as could ever be expected.

 

Without question, the batwing air cleaner is one of the ugliest air cleaners ever made----------------------BUT DAMN, THEY ARE COOL!!!!!!!!!!!!

Over 45yrs ago, I got my first (and only) set of matched 2x4 carbs. I put them on the 56 Corvette. Some years later, I replaced the 2x4 setup with FI, and they have sat on the shelf ever since (about 35yrs), in a plastic bag with 2 packs of desiccant in the bag.
A few years ago, SOMEONE had bought the tooling that was used to reproduce the batwing air cleaners: one for the 56, one for the 57 without deluxe heater and one for a 57 with deluxe heater. I bought a batwing for a 57 with a deluxe heater, and stuck it away for the future.
Several months ago, when I had to pull the SB389 out of the 51 because of a busted piston, it had an early Z28 intake and Q-jet. I vowed that when it went back together the 2x4s and batwing would go on it. DONE!

Somewhere along the way, when I was looking into buying a repo batwing, it was explained to me that many years ago when the batwing was previously reproduced, they were all sold and the tooling was stored away (somewhere). A person came along and bought the tooling, refurbished the tooling and started making batwings again. Expensive? Yes, but taking all things into consideration (including the price of an original), I felt the price was acceptable, so I bought one-----------------ZERO REGRETS!!!!!!!!!!!!
I personally do not have an original for comparison, but the one I bought seems to be of the utmost quality and construction. I can recommend buying one of the newer repos!

To get it to fit on the 51, I had to turn it around in order to clear the air cond compressor. PERFECT fit!

 

I recently had one of the repro's in my shop. I picked it up with a bunch of 57 dual quad parts a friend of mine bought. I met the seller at Bowling Green and carried it back.

The unit looked nice, but I could tell the gauge of metal, or iron in the metal was not the same. It weighed a few pounds less. When you "thumped" it, it was more tinny sounding.

Yes there are not many that can tell the differences, I may be of the last ones......

I have one Original OEM that I am restoring for one of the members here. I also have 2 center sections from Packard's that I am converting to the Chevrolet carb spacing.

If you compare the Chevrolet air cleaner body to the other makers you will notice the spacing between the carb stacks is different. The stack that is on the pointed end of the Chevrolet air cleaner is closer the edge. This was done to move the whole body of the air cleaner further forward for firewall clearance. The metal stamping in this area is also different on the bottom stamped section. Some of the early conversions didn't do this and you could just look at the point and know it was converted.

The one with bare metal showing is the OEM Chevrolet example.

Mikey