So the application is an original unmolested 1973 F250 Camper Special with a 390, build date of 5/73, running the original 21xx series carb. I have documentation to support the 44k miles on the clock and it has been in the family 22 years, purchased with 23K miles on the clock. I recently pulled the truck out of long time storage, rebuilt carb, cleaned tanks, stuff you always do when pulling a vehicle from storage. It ran OK.
But, I don't think the truck had ever developed the power I though it was capable of. I pulled the carb and found the thin spacer between the one inch aluminum spacer and the manifold to have a 5/32" restriction about half way around both openings. Number on the spacer D3TE 9447 CB. Is this spacer a manufacturing defect or why would did Ford purposely put a restriction in the intake? Better low end response? I am doing a few other things to the truck and might get a chance to take it out on the road tomorrow but in the meantime, what do I have here?

 

Watching this. Don't have a clue, but just doesn't look right. Looks like a mismade gasket.

 

This is not a spacer...

Marked: D3TE-9447-CB = Ford part number: D3TZ-9447-J .. GASKET-2V Carburetor Spacer Plate to Intake Manifold (Motorcraft CG-412A).

Applications: 1973 F100 360 / 1973/74 F100 390 / 1973 F250/350 390.

 

Thank you very much for the correct nomenclature ND, kind sir. The original question was posed to ascertain if the part was defective or was Ford attempting to alter the performance of the engine. The gasket pictured is multilayer, metal and probably asbestos, gasket. I thought perhaps someone with your vast experience and knowledge could bring light to my question. I thought if perhaps it was a special part, designed to alter performance it may be called such.
Given the limited application, I am suspecting it may be designed to alter performance.

 

This composition gasket is thick because it was used with the EGR valve (first year: 1973). Without an EGR valve, both the upper (carb to spacer) and lower (spacer to manifold) gaskets are paper, and thinner than a dime.

The original factory installed EGR spacer plates were aluminum and heat could cause them to melt internally, I kid you not.

Ford later came out with cast iron EGR spacer plates for use as service part replacements. The same upper/lower gaskets were used w/the cast iron spacers.

 

That's the EGR spacer plate to manifold gasket. Looks like a gasket manufacturing defect to me. The imprints of the spacer look round, but the gasket opening does not. It wouldn't make sense to make a restrictor plate out of a gasket, or make it asymmetrical. Replace it with a quality Fel Pro gasket, which will be like the original. Don't use one of the paper-thin replacements (those will burn out).

 

Another cause of low power in trucks with single exhaust is some of the Y pipes are incorrectly made. What the problem is , where RT and Left sides join togather the hole is incorectly cut. Some are very rough and very small, sometimes as small as a dime. Iv'e found this in factory and replacement Y pipes. This has caused a lot of problems with burned and receded valves. Not all are this way .

Have A Good Day ----- Hotwrench