1963 AFB Carb Air Cleaner Stud Length

[Greg S.]

I'm in the process of rebuilding my 3461 carb for my 300 hp engine. The carb is not original to the car, it came off of an Impala. The air cleaner stud appears to be far too tall for my air cleaner. Can anyone tell me what the length of this stud should be for my car? Also how is the stud held in,threaded or is it press fit; and if it is press fit what's the technique to get it out? Thanks!

1963 300 hp engine

[Stuart F.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Greg;

If no one gives you a measurement before tomorrow, I'll be glad to check one of mine in the morning. As for the method of attachment, it is threaded into the carb body through the top plate and actually forms the main attachment of the two sections along with the perimeter screws.

I use two nuts jammed together, then apply a wrench to the lower nut turning CCW to remove the stud, and on the upper nut CW to reapply it (don't use a vice grip on the smooth shaft portion cause it won't look pretty no more).

Did you actually find a 3461 on an Impala? Do check the carb specs for your 63's 3461S model relative to jetting and adjustments to be certain it is correct for your application.

Stu Fox

[David L.]

Re: 1963 AFB Carb Air Cleaner Stud Length

To remove the air cleaner stud I use two 1/4-20 nuts jammed together with a lock washer between them. It works every time without any damage to the stud.

I believe that the 3461 uses air cleaner stud # 3777266 which is 1/4"-20-20 X 3 1/4" long.

Dave

[Greg S.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Stuart and David,
Thanks for the replies. I did find the carb on an original 300 hp Impala SS car. I assume the carb jetting would be the same for both the passenger car and Corvette because the engines were essentially identical. With that said I'll do some more research and make sure; I'm always surprised about subtle differences GM created!

[David L.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Greg,

How long is the 63 Impala 3461 carb stud, GM # 3756988 as shown in the 63 Chev AIM.?
Also, the lengths of the threads.

Dave

[Clem Z.]

Re: 1963 AFB Carb Air Cleaner Stud Length

one day at time trials on a 1/2 mile dirt track i was having carb trouble in the turns so installed a carb from a tin car and in the rush i forget to remove the longer air cleaner stud. it put a nice hole in the hood when i shut it. if you have a 59 vette with a patched hood over top of the carb that could be my car.

[Greg S.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Dave,
The stud length is 3-1/2" and the threaded portion is 1-1/2" long.

[Stuart F.]

Re: 1963 AFB Carb Air Cleaner Stud Length

My original is 3-1/4" long. Initial thread into carb is about 5/8", shank portion is 3/4", unthreaded is 1" and threaded end is 3/4". Total above top of carb is 2-3/8" to 2-1/2".

Stu Fox

[David L.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Greg,

I normally do not buy reproduction parts but in your case I think that finding an original 3777266 air cleaner stud is going to be very difficult. Paragon Corvette and Corvette Central sell repros and they do look correct.

Dave

[Stuart F.]

Re: 1963 AFB Carb Air Cleaner Stud Length

Along with my original stud, I also have picked up several repro studs over the years as I have several carbs that I play with on occasion. If I put them side by side, I can see no differences. I prefer the repros as the cad plating is better, and I also learned not to use a vice grips on them as I did on my original. They are cheap and available from many Vette parts sources. Not really something to be too concerned about.

FWIW, I have my carb raised 1/2" with a 3/8" phenolic spacer plus two gaskets and I still have plenty of hood clearance with my stock air cleaner.

Stu Fox