I've always known my car, a 64FI built Nov 63, had the wrong fuel pump. When Joe C. put his article in the restorer I became motivated to fix this. I've read tons of stuff on this forum and think I have a picture of what 40083 should be. Some of what I'll share here is arcane and some will think I'm over the edge but I find it interesting.
Over the past 9 months I've acquired 4 pumps, three which I'm confident have not been rebuilt and the 4th I suspect hasn't either.
1. A service replacement built July 71, 40083GK (if you buy into the system Dave Liukkonen proposes), in a box dated 9/72 which may or may not be the original box. The seller says it was on his car for a short while but the box is original from when he bought it. Has all the features: mag top, S screws, copper plated cross head hinge pin, stamped steel bottom, looks near to new except dark splotches on the mag top.
2. Advertized as coming off a 65 for total rebuild and in working order: mag top, S Screws, Cross head pin, stamped bottom, "Made USA"(no IN) with extra bosses like the one Alan Drake posted pics of. Certainly the real deal.
3. As #2 but of unknown origin but with the 4 screw cast bottom with "AC". On this pump the screws holding the cast bottom do not have the S or the integral flange. They are standard fillister head with separate lock washers. I'm wondering if using lock washers and screws without the flange was common such that this pump might be correct and unmolested. I'm thinking it is.
4. Just like #2, probably off a 65 in the UK (haven't looked inside for date codes) except there are no S screws (but the screws have the integral flange) and the stamped bottom is attached just like #3, fillisters and lock washers. Since the original cross head hinge pin is in place it is unlikely this pump has had a total rebuild, but the pump body has been loosened from the top (mag) cover and the inlet rotated 3 positions clock wise (about 108 degrees) when viewed from the bottom. It is likely someone did this to accomodate a non-Chevy Small Block application or they had an issue and opened it to look and just didn't put it back right. In either case it doesn't make sense that the screws would have been changed. Does anyone have any evidence that some of these pumps were made without the S screws. Additionally the rocker arm on this pump has very neat and small part number on it 5621021; since the original hinge pin is in place this if factory but the other three don't have it. Also, this pump had a metal (rebuild) tag with 40083 and AC374 stamped in it. Again, with a virgin hinge pin I don't see how it could have been rebuilt and I'm wondering if someone knows what the AC374 means. Maybe this isn't a Corvette take off and is a 40083 sold into a different market.
I can post pics if anyone has a specific request but that's what I see so far. I plan to tear #4 down and rebuild it for my car.
Over the past 9 months I've acquired 4 pumps, three which I'm confident have not been rebuilt and the 4th I suspect hasn't either.
1. A service replacement built July 71, 40083GK (if you buy into the system Dave Liukkonen proposes), in a box dated 9/72 which may or may not be the original box. The seller says it was on his car for a short while but the box is original from when he bought it. Has all the features: mag top, S screws, copper plated cross head hinge pin, stamped steel bottom, looks near to new except dark splotches on the mag top.
2. Advertized as coming off a 65 for total rebuild and in working order: mag top, S Screws, Cross head pin, stamped bottom, "Made USA"(no IN) with extra bosses like the one Alan Drake posted pics of. Certainly the real deal.
3. As #2 but of unknown origin but with the 4 screw cast bottom with "AC". On this pump the screws holding the cast bottom do not have the S or the integral flange. They are standard fillister head with separate lock washers. I'm wondering if using lock washers and screws without the flange was common such that this pump might be correct and unmolested. I'm thinking it is.
4. Just like #2, probably off a 65 in the UK (haven't looked inside for date codes) except there are no S screws (but the screws have the integral flange) and the stamped bottom is attached just like #3, fillisters and lock washers. Since the original cross head hinge pin is in place it is unlikely this pump has had a total rebuild, but the pump body has been loosened from the top (mag) cover and the inlet rotated 3 positions clock wise (about 108 degrees) when viewed from the bottom. It is likely someone did this to accomodate a non-Chevy Small Block application or they had an issue and opened it to look and just didn't put it back right. In either case it doesn't make sense that the screws would have been changed. Does anyone have any evidence that some of these pumps were made without the S screws. Additionally the rocker arm on this pump has very neat and small part number on it 5621021; since the original hinge pin is in place this if factory but the other three don't have it. Also, this pump had a metal (rebuild) tag with 40083 and AC374 stamped in it. Again, with a virgin hinge pin I don't see how it could have been rebuilt and I'm wondering if someone knows what the AC374 means. Maybe this isn't a Corvette take off and is a 40083 sold into a different market.
I can post pics if anyone has a specific request but that's what I see so far. I plan to tear #4 down and rebuild it for my car.