Real Cobra intake manifold

[260]

Hello, newby here.... I have a 260 in a Model A coupe hotrod that was purchased over 40 years ago. Has not been touched in that long as well. The engine has a "cobra" intake manifold on it, and wanted to determine if it was a "real" cobra manifold or a take-off/aftermarket. My dad bought the car in '74 as a project for my brother and I... been dragging it around for the last 40+ years... Does anyone recognize this particular manifold? (don't laugh too much and hurt yourself) Thanks, Ed

[LMH]

Is there an "S1MS-" number cast into the manifold behind the carburetor?
Larry

[CompClassics]

What size NPT thread is used for the water temp sending unit?

[260]

Hello Fellas, thanks for the Q's. I will have a look tonight and let you know. But I do not remember seeing any numbers behind the carb...

[260]

Good evening, the rear of the manifold is partially under the firewall, but used an inspection mirror and could not find any markings. The only way I knew to measure the water temp sensor threads was by using wrench sizes, a 3/8 would just not get around it, but a 10MM fit nicely.. Not sure if this helps.. buy was sure hoping those markings were there... Thanks, Ed

[LMH]

In terms of the Cobra, a factory installed high rise intake like you have would be EXTREMELY rare. More than likely, it's an early GT350 intake. Based on it's age, I think it's an original manifold though.
Larry

[cycleguy55]

Originally Posted by 260

The only way I knew to measure the water temp sensor threads was by using wrench sizes, a 3/8 would just not get around it, but a 10MM fit nicely.

That sounds like 1/8" NPT.

[260]

Thanks again fellas! Based on the information you have provided, I looked up the GT350 manifolds and found the following: Sounds like I may have a very early one based on the area I bolded below. Thanks again!

Intake Manifold
Variations in the "small COBRA lettered" intake for the 1965 GT350 street cars had to do with the location of the firing order embossed onto the intake as well as the S1MS-9424-A part number.

The very early GT350 Mustangs, up to about serial number ??, did not have a Shelby part number on the Cobra intakes. These were also the manifolds used for the 289 Cobra street cars as the optional "hi-rise intake" while the cars were at the Venice factory.

Most of the 1965 GT350 production intake manifolds had the Shelby American part number on the top of the rear runner behind the carburetor. The firing order was usually located on the far back, top, flat pad of the intake. Areas to look at if an intake is an original or a reproduction is the opening where the carburetor is mounted. The original intakes have four circular holes whereas the reproductions have oval slots openings. The 1965 and early 1966 intakes also have a stamping on the underside, near the front. It is on a round, about 1 inch in diameter, plug like casting. It reads OECO , which in short, stands for Offenhauser Equipment Company, the manufacturer of the manifold. The intakes were machined by Dearborn Steel Tubing. My intake also has the letters J N as well as A WL, which may have been stamped years later as a means of keeping track of it. The rear of the small lettered intake has another one of these 1" raised round plug castings, mine has a strange 303 with a very, very small 6 next to that.

Just for comparison purposes, the competition GT350 intake had no PCV hole or electric water temperature sending unit holes drill and tapped. PCV valves were not used on the race cars. Water temperature was monitored by a mechanical gauge which had its sending unit installed in the hole usually used by the heater hose.