85lebaront2 Posted September 14, 2023 Share Posted September 14, 2023 No, but I leave town tomorrow morning for Gary's show (and a buddy in MO before that). And I want to take the carb to the show (since if it's useless to me, might as well rehome it). Found the "correct" carb for it... $1000: https://www.holley.com/products/marine_and_powersports/marine/marine_carburetors/parts/0-80364 Yeah, I better hope for a used unit. Heck, that's not far off a marine sniper EFI for the same setup: https://www.holley.com/products/marine_and_powersports/marine/sniper_efi_marine/sniper_efi_4150_marine/parts/550-510 (although that'd be a lot of fuel system mods... and no idea how/if an O2 sensor would fit there). Maybe look for a used carb? What that Mercruiser had originally was a 302 two barrel intake with an adapter and a Rochester 2GC marine carburetor. My department manager at NNS had one. Engine should have 351W heads. The D4HE prefix is 1974 model year for introduction, but could easily be later. If you could find someone with a big truck that used the SD engines and needs a carb it would be great. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 14, 2023 Share Posted September 14, 2023 What that Mercruiser had originally was a 302 two barrel intake with an adapter and a Rochester 2GC marine carburetor. My department manager at NNS had one. Engine should have 351W heads. The D4HE prefix is 1974 model year for introduction, but could easily be later. If you could find someone with a big truck that used the SD engines and needs a carb it would be great. Bill - Specifically a 475 or 477. Link to comment Share on other sites More sharing options...
85lebaront2 Posted September 14, 2023 Share Posted September 14, 2023 Bill - Specifically a 475 or 477. Thanks Gary, I knew it came off one of those old SD gas engines as I rebuilt a few for the cities of Hampton and Newport News VA. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 14, 2023 Share Posted September 14, 2023 Thanks Gary, I knew it came off one of those old SD gas engines as I rebuilt a few for the cities of Hampton and Newport News VA. I would have thought that a carb for a 475 would be too rich for a 302. But maybe that's not the case? And, for what its worth, a buddy of mine had a Cobalt with a 302 in it back in the 70's. It had a 2bbl intake and carb on it and we put an Edelbrock intake and 4bbl on it without much difference. Yes, it had a little bit more on top end, but not much. And there was no discernable difference coming out of the hole. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 14, 2023 Share Posted September 14, 2023 I would have thought that a carb for a 475 would be too rich for a 302. But maybe that's not the case? And, for what its worth, a buddy of mine had a Cobalt with a 302 in it back in the 70's. It had a 2bbl intake and carb on it and we put an Edelbrock intake and 4bbl on it without much difference. Yes, it had a little bit more on top end, but not much. And there was no discernable difference coming out of the hole. Gary, it's not about "too rich", a carburetor meters fuel to air. An oversized carb is more likely to be too lean because the smaller displacement wouldn't provide enough signal (depression) to suck fuel. Regardless, Larry needs a carb that fits his manifold, and that's obviously a 4V at this point Looking at 1975 Mercrusiers with a 302 I see this: https://www.mercruiserparts.com/888-2-bbl-ford-302-v-8-1971-1977-31 I will definitely try to pick Tommy's brain while y'all are having a truck gathering. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 14, 2023 Share Posted September 14, 2023 Gary, it's not about "too rich", a carburetor meters fuel to air. An oversized carb is more likely to be too lean because the smaller displacement wouldn't provide enough signal (depression) to suck fuel. Regardless, Larry needs a carb that fits his manifold, and that's obviously a 4V at this point Looking at 1975 Mercrusiers with a 302 I see this: https://www.mercruiserparts.com/888-2-bbl-ford-302-v-8-1971-1977-31 I will definitely try to pick Tommy's brain while y'all are having a truck gathering. Ahhh! That makes sense. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 14, 2023 Share Posted September 14, 2023 Ahhh! That makes sense. I'm seeing an Edelbrock knock-off 1409 "marine" carburetor on Amazon for under $200.... All the usual caveats about Chinese 'junk' apply, but it's worth knowing about. Edit, link didn't work: Trucktok 1409 Marine Carburetor Performer 600 CFM 4 Barrel Square Bore with Air Valve Secondary Electric Choke Carburetor Replacement for Chrysler Chevy Marine Engine https://a.co/d/4jWRQlD Link to comment Share on other sites More sharing options...
ratdude747 Posted September 14, 2023 Author Share Posted September 14, 2023 No, but I leave town tomorrow morning for Gary's show (and a buddy in MO before that). And I want to take the carb to the show (since if it's useless to me, might as well rehome it). Found the "correct" carb for it... $1000: https://www.holley.com/products/marine_and_powersports/marine/marine_carburetors/parts/0-80364 Yeah, I better hope for a used unit. Heck, that's not far off a marine sniper EFI for the same setup: https://www.holley.com/products/marine_and_powersports/marine/sniper_efi_marine/sniper_efi_4150_marine/parts/550-510 (although that'd be a lot of fuel system mods... and no idea how/if an O2 sensor would fit there). Maybe look for a used carb? Before leaving town, I scanned some of the documents from the glove box. They're not pretty but it's something. But, being images, they're too big to upload. If we want them here, I'll be happy to provide. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted September 14, 2023 Share Posted September 14, 2023 Before leaving town, I scanned some of the documents from the glove box. They're not pretty but it's something. But, being images, they're too big to upload. If we want them here, I'll be happy to provide. It doesn't work to use the 'large size' option in the right column of the insert image window? Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 14, 2023 Share Posted September 14, 2023 On a side note, I have an idea for a good high output ignition system that hopefully can be triggered with a DS-I or DS-II distributor (it would still need the large cap and rotor but use a E-core coil and no ballast resistor. If you or someone else has a DOA DS-II box (can even be aftermarket). The issue will be if a DS-II pickup will trigger the module, I know a Chrysler pickup will as that is what is used on MGs and Jaguars. Bill - I rescued this yellow-grommet module from the stuff going to the show. Seriously doubt anyone would buy it, even for a buck which is what we'd be asking, so it would get tossed at the end of the day. As you can see, two of its connectors are broken and being a yellow-belly no one wants it. It is now with the other stuff coming to you - some day. Link to comment Share on other sites More sharing options...
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