'65 396/425 Exhaust Manifold Choke Tube

[Mark S. Lovejoy]

A few weeks ago I posted a question regarding the install of the choke tube inside the exhaust manifold, thanks to those who responded.

The question now is; should the installed choke tube extend outside the manifold? If so how much?

Or; should the tube ends be recessed into the manifold.

Final Question; How should the two choke tubes from the carb connect to the manifold tube?

Could someone with an original example provide a picture?

Thanks,

Mark

[Wayne M.]

Here's my observations

The external tubes are currently installed on my 3856302 manifold, and I seem to recall (without removing them) that both the forward/upper and the rear/lower ends of the inside heat tube are recessed about 1/4" into the cast iron. Then, both the clean/cold air tube (from the tube on the carb inlet flange) and the hot air outlet tube from the forward exh. manif. to the carb choke stove, are interference-pressed into the exh. manif., to abut against the internal tube.

There's an overall X-section of this manifold in Colvin's '65-69 Chevy book, but no details of the tube area, except that it would appear on section "AB-AB" of the GM drawing (which is not reproduced in Colvin's book).

Sorry; no picture, but not sure that one would help.