Stock 273 4bbl intake question

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cudamark

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Has anyone figured out why they made this threaded side car on some of the 273 4bbl intakes? It's a blind hole, so, it's not a passageway to anywhere. I don't know of anything that would mount there, especially with that big a hole. It's a C.A.P. intake if that makes any difference to anyone.

intakebump.jpg
 
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Here is my take on it. Being it is threaded for a bolt and not a pipe plug it was there for a bracket mount. Chrysler sold alot of engines that were used commercially and in farm equipment. I have seen slants, 273, 318 and 400 engines power all kinds of farm equipment.
 
I've had at least a dozen of them over the years and was always curious as to the official reason for their purpose. Am I correct in my assumption that they're all the C.A.P. version, or does someone have a different casting with that same feature?
 
I've had at least a dozen of them over the years and was always curious as to the official reason for their purpose. Am I correct in my assumption that they're all the C.A.P. version, or does someone have a different casting with that same feature?
Yes what I found and posted is they are all the cap version also used on the D Dart and in industrial and marine applications. The hole being threaded for a bolt was for a mount bracket in an industrial application in a 273 or 318 in 1966 or 1967 engine.
 
Here's a 66 non CAP manifold. It doesn't even have the casting boss for the hole.

20210513_091421.jpg
 
Just for reference here is my 2-bbl CAP intake, no extra port, CAP valve connects to the standard vacuum port.
2018-06-19_001.jpg


Alan
 
Here is my take on it. Being it is threaded for a bolt and not a pipe plug it was there for a bracket mount. Chrysler sold alot of engines that were used commercially and in farm equipment. I have seen slants, 273, 318 and 400 engines power all kinds of farm equipment.
That would one hell of a mounting bracket with a hole that size. Marine/commercial/industrial wouldn't have had the C.A.P. requirement that year, so, why would they use that manifold and not the non C.A.P. version? This casting was mainly a Ca. requirement. All the marine/commercial/industrial stuff that I've seen were only 2bbl engines and I haven't seen any of those with that casting add-on.....as Cuda Al's 2bbl C.A.P. photo shows.
 
That would one hell of a mounting bracket with a hole that size. Marine/commercial/industrial wouldn't have had the C.A.P. requirement that year, so, why would they use that manifold and not the non C.A.P. version? This casting was mainly a Ca. requirement. All the marine/commercial/industrial stuff that I've seen were only 2bbl engines and I haven't seen any of those with that casting add-on.....as Cuda Al's 2bbl C.A.P. photo shows.
Check my other postings in this thread and you will see that one is marine specific. As far as the size of the bolt for a bracket I take it you have never been around farm machinery before. The equipment back then was built to last and I am still using a loader tractor from 1948.
 
I've played with a few tractors, and quite a bit of industrial stuff. Never saw a stock 4bbl on any of them though. The marine engines I've had didn't even have accelerator pumps in the carb. Some forklifts don't either. They just weren't set up for high performance.
 
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