Mechanical Part Pictures
Early Bullet Air Cleaner
An original set of 53 54 corvette Boettger air cleaners. You can tell they are original because the first "p" in the second row of letters starts on the left side of the O in Boetteger. When they made the repo's they got the letters crooked.

NOTE - I believe the cleaners pictured above may not have the original screws. I believe the original screws were very large round heads and chromed. Also, I do not believe that locking washers were used. (53 and early 54 experts - please feel free to weight in).



Late 54 Dual Pot Air Cleaners
Chevrolet went to the Dual Pot Air Cleaners after 54 #2911 or so. The dual pots featured chrome lids, secured by stamped wing nuts. Click on the picture on the left to see what original wing nuts look like.

The picture on the right shows the inside of a lid. A heavy coarse brillo pad like fabric is secured to the top of the lid by the three pronged retainer. The retainer iotself is secured to the lid by a brass rivet. You have to kill the rivet to remove the fabric.

Restoration note - The coarse fabric was reproduced years ago. But the 53-55 dealers no longer carry the item. I found a couple on ebay just days before having my car judged. Thus, if you need the fabric, keep you eyes open and buy it when you find it.



1955 Air Cleaners
Original 55 corvette air cleaner was steel chromed one piece , inner fire protection material and support was held on by three spot welds NOT a brass ring. Original bottom area was painted a gray in color. In the pics above, the far left pic shows a correct looking reproduction. The middle picture and the picture on the far right show NOS pieces.

First design had a egg depression in the bottom lid to clear the first design Carb and choke housing. Second design did not have the egg depression because the Carb was redesigned as a second design Carb .

PS first pic. Is a repro but correct looking other two are NOS



Coil
This orginal 6cyl. Corvette coil was a #394 coil. #394 was manufactured soley for early Corvettes. Shortly afterwards, Chevy replaced the #394 coil with the passenger car #380 coil. See the picture on the top row, far left, which shows a #394 coil and a #380 coil side-by-side. For NCRS judging, you can turn the numbers of the coil and have the numbers be unreadable. You still get full point value if your coil looks correct with the numbers unreadable.

There is a difference in tops between the #380 coil and the original #394 coil. In the bottom row of pics, the #380 top is on the left, and the #394 coil is in the middle. The text is lighter and a bit larger on the #380 coil, and there is a "BH " near the positive screw of the #380. On the bottom row, far right, is a picture of the tangs that should be on the coil. Note the tangs fit into the holes provided.

On the top row, far right, is the 1955 Corvette setup. The 55 Corvette used a 12 volt #086 coil having a cad (not black painted) finish. Also note that the mounting bracket is cad plated and has NO area for a condenser to be mounted. (The NCRS manual states that 53-54 mounting brackets are "generally without a condensor mount-tab.")



Distributor
The original 6cyl Corvettes came with a distributor bearing the part number (1112314) and date code. The pic on the far left is an original 1953 distributor found in 53 #241. The date code is 3E1 - may 1, 1953. GM reproduced the 1112314 distributors in the early 1970s I believe. These distributors were identical to the originals, except the reproduced units used a plastic grease cap. Originals used a metal grease cap. These grease caps could be swapped for each other however.

The second picture from the left is a GM reproduced unit - bearing a date code of 4J19. This unit had a plastic grease cap.

The second picture from the left is a modern face plate reproduction. This allows people to change the date of their face plate - something important only for NCRS judging. If you look closely, the font on the reproduction is slightly different. Thus, a trained eye could probably discern original from reproduction.

The picture on the far left is the GM reproduction. Note that the condenser is attached to the outside of the distributor. Some Chevy trucks featured tach drive distributors, and those distributors will work (somewhat) on 6 cyl Corvettes. The truck distributors apparently have a problem with higher rpms. You can tell the truck distributor from the Corvette distributor by (1) the part code on the face plate, and (2) the condenser for the Chevy truck distributor is located INSIDE the distributor housing.


Distributor Vacuum Advance - 076
Original vacuum advance on the top right, later produced advance on the top left. There are a number of differences. The original has many marks for octane selection below the 076 cast number (see bottom right pic). Later replacements do not. The original has a different fitting for where the vacuum advance line connects (see bottom left for original). And the original has the copper part. Near the distributor holder.




Engine Pads
I believe these to be original engine pads. The LAY pad is from a 1953. The YG pad is from my 54.

Original 54 pads appear to have the first 5 numbers gang stamped. The next two numbers appear hand stamped, and usually are heavier and larger than the other numbers. The last 5 digits and letters again appear gang stamped.



Exhaust manifold
Corvette only exhaust manifold carries a casting number of 3836108 and a date code on the inside, that cannot be seen during judging. The above manifold is an original.



Corvette Heat Riser
6 cylinder engines heat control valve is blocked in "heat off" position by placing thermostat spring in backwards. The pic to the right shows the correct setup, which also features a block off plate.

The pic on the right shows an original design 55 corvette heat riser. #3721512 is "casted" into the counter weight and was never a square design counter weight like 56 Corvette.



Exhaust manifold retainers
Original corvette exhaust manifold retainers are solid. Passenger car retainers are like canoes - dugout on the backside of the retainer. You can tell if a Corvette has the originals by slipping a finger around the retainer and feeling for the dugout. If solid - the car has original retainers.



Exhaust Flange
Originals on the left are solid cast iron with a casting number. Reproduction on the right is stamped steel.



Fuel Filter
Original fuel filter has large AC stamped on top dome, and uses a granular (as opposed to paper) filter element. The top row of pictures shows an original top and filter. Be careful when you buy one of these. The top lids can bend thru over-tightening. I am starting a collection of filters that leak when installed because of a bent lid. My advice - bite the bullet and buy an NOS filter. That way you are sure that your filter will not leak.

The bottom row of pictures shows the later GM replacement top and paper filter.



1954 Cylinder Heads
The picture on the right shows an original 1954 cylinder head. Original heads carry casting number 3836241. This was a Corvette only part. Unfortunately, these heads were VERY subject to cracking.

You will find a lot of 54's with passenger car heads. It is possible to make a passenger head look like a real 241 head. One technique involves carving off the casting numbers from a passenger car head, and then using J-Weld to put the 241 head numbers on. The numbers usually are only somewhat attached to head, however. A pocket knife can discern the fake from the real thing. Also, a real 241 head has carries a 241 code on other places of the head, none of which can be read easily if the head is on the car, however. The middle picture shows one of the 241 codes on the passenger side of the head. This code is covered by the chrome water tank and bracket, however.

The picture on the far right shows a passenger car head temperature sender adapter. In a real 241 head, the temperature sender does not require an adapter - the temperature sender screws right into the head. On the passenger car head - you often need the adapter. Thus, if you see a 241 head with a temperature sender adapter, you are likely looking at a passenger head.




Water Pump and Base Unit
Expensive Corvette only parts. I believe the above pics to be original parts. Pumps have casting number 3706011, and the adapter base plates have casting number 3706013.