I'll be damned if I can find that casting# ??? As previously noted, the casting numbers I've found (beginning with the digits 374) speak to 1957 engines.
Back to your date code. K 6 7 says to me - Nov 6 1957. So, I scoured Chevrolet's "Master Parts and Accessories Catalog" and the nearest thing I can find is in the 1958 supplement...
I can only surmise, your manifold casting was a revised design of the above #3746829...
Could this be a marine or industrial application? I dont remember seeing that pipe plug on any other manifold of this type. You can see the plug between the heat riser passage and the intake runner, maybe for a crankcase vent or pcv hookup?
Something from 1958 is my guess. Has to be Saginaw or Tonawanda cast as McKinnon weren't doing 4BBL intakes at that time. Is it an AFB Carter pattern carb?
THe plug is what got my attention when i bought it,that is where the oil returns from the oil filter on a 1955 chev engine,one year only.But that is not the 1955 number.Pics are carb that was with it. Thanks Percy
Interesting about the oil filter return line hookup, I havent seen one before. It is possible that GM used the 265 engines in industrial and marine applications longer than in passenger vehicles. Also I am not sure if the truck engines got the full flow oil filter in 56, it may have been later. Interesting manifold, it would be nice to learn the history of it.
This is all I could find on these 2 numbers. 3746826- 265-283 1956 to 1963 2 barrel carb. 3746829-283-327 1957 to 1961 4 barrel aluminum corvette 230 HP with WCFB four barrel.
I'm confused!!!Oil filter picture is a 2 BBL intake and others are 4 BBl. The 4 BBL carb is not a Carter WCFB but is a Rochester 4 V used up to 64 [ same design as my 64 Chev 409 uses] Could be a truck manifold, & has no provision for choke T/stat spring ,so it used heat tubes to exh. manifold to bring hot air up to choke spring on side of carb. Threaded fitting shown in one of pictures.
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Some times I wake up GRUMPY, but today I let her sleep in !!!!!!!!BLACKSTOCK Ont.
I'm confused!!!Oil filter picture is a 2 BBL intake and others are 4 BBl. The 4 BBL carb is not a Carter WCFB but is a Rochester 4 V used up to 64 [ same design as my 64 Chev 409 uses] Could be a truck manifold, & has no provision for choke T/stat spring ,so it used heat tubes to exh. manifold to bring hot air up to choke spring on side of carb. Threaded fitting shown in one of pictures.
I think he posted the photo of the 2 bbl intake with the remote oil filter as a clue of what the pipe plug might be for.
I'm confused!!!Oil filter picture is a 2 BBL intake and others are 4 BBl. The 4 BBL carb is not a Carter WCFB but is a Rochester 4 V used up to 64 [ same design as my 64 Chev 409 uses] Could be a truck manifold, & has no provision for choke T/stat spring ,so it used heat tubes to exh. manifold to bring hot air up to choke spring on side of carb. Threaded fitting shown in one of pictures.
That's right for the 2 barrel, showing the plug. The picture is a Rochester 4 V. What the information on intake # 3746829 that is not shown is it was a aluminum corvette that came with a WCFB.carb.
I just got thinking about the bigger trucks in the 50s. If the truck had an air compressor for the brakes maybe the plug would be where the oil for the compressor would return to the engine.
I don't think many trucks used 4BBL carbs though. In the GM Tech centre docs for trucks there are some higher performance 4BBL engines but almost always for El Camino. A couple of 4BBL do exist in the later 60's like a 4BBL 327 low comp 240hp L30 in 1968-9, but normally they were 2BBL for more torque.
I wonder if it is off an obscure Marine engine or a Studebaker? McKinnon did make that sort of stuff and did use casting from other foundries if they didn't make them themselves. Although I think al the Studebakers with McKinnon SBC design engines were 2BBL and were black painted.