I am confused??? The latest NCRS Judging manual for the 70-71 Corvette says the the correct smog pump bracket is part number 3923214 for the 350 small block LT1. It says that 3923214 should be stamped on the edge of the long support of the bracket that faces down when installed and also attaches to the water pump bolt. I have seen a lot of so called original smog pump brackets that do not have the part number stamped as stated in the manual but are instead stamped on the underside of the bracket in a small square area, leaving the long support edge clean and "untouched". What is the correct stamping and the NCRS correct assembly line bracket that should be used for the 70-71 Corvette 350 LT1??? I have attached some photos of the differences.
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Re: What is the correct smog pump bracket for 1970-71 Corvette 350 LT1?
Tom------
My late 1969 has the bracket with part number location as shown in your first photo and as pictured below. I expect that 1970 would have been the same. However, it's possible that both part number locations were used, perhaps even at the same time. It's unlikely, but possible. As far as GM was concerned, the brackets were identical. Most likely, the difference in part number locations was a function of what foundry was casting the part or, perhaps, what pattern was used. By the way, the part number location seen in your first photos and in my photo is, by far, the most common location seen on these brackets. I would say the location seen in your last photo is actually rare.
The GM #3923214 bracket was a Corvette-only piece. It was used for all Corvette small blocks with AIR from 1968 to 1977. For 1978 it was replaced by GM #14007354 which also became SERVICE for 1968-77 in July, 1981. The 14007354 was discontinued without supersession in September, 1994.
DSCN3919.jpgIn Appreciation of John Hinckley -
Re: What is the correct smog pump bracket for 1970-71 Corvette 350 LT1?
Joe, Thank you for the info and the photoComment
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Re: What is the correct smog pump bracket for 1970-71 Corvette 350 LT1?
Joe, I am in agreement with you that both styles of part number were used somewhat interchangeably. I am surprised, though, that you indicate that was a Corvette-only part. They seem to be extremely common for being Corvette-only.Comment
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Re: What is the correct smog pump bracket for 1970-71 Corvette 350 LT1?
Mike------
Yes, these brackets seem very common and often sell for fairly low prices. I've always been surprised that there seem to be so many around. However, I've checked pretty thoroughly and the only original application I can find for the 3923214 is 1968-77 Corvette small block with AIR. Of course, even in this range not all Corvettes were equipped with AIR so the source of donor cars is not even all 1968-77 Corvette small blocks. I've even checked MD trucks, which occasionally use the same engine components as Corvette, and they did use this bracket.
All I can figure is that there were enough of these AIR systems removed (VERY UNWISELY) from 1968-77 Corvettes to well supply the used marketplace. Plus, these brackets are obviously not a wear part so the only folks that need them are folks with 1968-77 Corvettes originally equipped with AIR that want to restore to the car the removed system. One strange thing: while the brackets are plentiful, the diverter valves are anything but.In Appreciation of John HinckleyComment
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