'57 Exhaustr Manifold # 3733976

[Pierre J.]

Few weeks ago, I bought right exhaust manifold (#3733976) for my '57 on eBay. I decided to install a new choke tube in it as the one in the manifold was damaged at the top.

I got a new one from Paragon but it has far less restrictions in it then the one I removed. I am a bit concerned this will affect proper choke operation.

Were there different choke tubes for these manifolds? i thought they would be all the same even for full size Chev?

Thanks,
Pierre 34410

[William C.]

Re: '57 Exhaustr Manifold # 3733976

I guess you would have to explain "restrictions", as the originals are straight thru top to bottom

[Pierre J.]

Re: '57 Exhaustr Manifold # 3733976

I guess you would have to explain "restrictions", as the originals are straight thru top to bottom

The two that I have are not "straight thru" The original that was in the manifold is "pinched" pretty well all the way and the Paragon only has a slight pinch near the bottom. I beleive these restrictions are to control the amount of heat going to the choke coil.

[Roy B.]

Re: '57 Exhaustr Manifold # 3733976

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[Richard M.]

Re: '57 Exhaustr Manifold # 3733976

This is a picture from the zip store. Says 57 to 65. The end(top or bottom?) is swedged to hold it in?
Rich

[Pierre J.]

Re: '57 Exhaustr Manifold # 3733976

Here is a few pic's of what I'm talking about. Clearly the new tube from Paragon has a "build in" restriction near the base of the tube (as pictured in the Paragon catalog). The other (original) tube has much more restrictions all the way down the tube.
My concern was, how will these differences affect the proper functions of the choke?
Pierre

[Doug F.]

Re: '57 Exhaustr Manifold # 3733976

i believe you are referring to the corrugated tube i've seen on some manifolds, it's to increase the surface area to allow it to transfer heat better and reduce air flow, the smooth tube will work just fine, doug

[John H.]

Re: '57 Exhaustr Manifold # 3733976

I've never seen one crimped/constricted like that one before; typically they look like the photo below.

[John N.]

Re: '57 Exhaustr Manifold # 3733976

Looked at one manifold from a 56 Corvette and one from a 57 Corvette. Both manifolds original to Corvettes and both were pinched. Can not verify if the tubes had been replaced at one time. I would not worry about the function of the new tube.
Regards