I think(pretty sure) I’m about to receive two 4gc carbs(probably compleat cores) from a gear head friend who is trying to move his stuff to a new smaller place. I have gotten a peak at them a year or so ago and I don't remember any tags on them. As he remembers, they are probably mid-sixty Chevy or Buick, but that is just a guess. My question is if the linkage can be adaptable to my 55 and the jets and rods can be changed if necessary is there much difference in the later cabs from the mid-fifties units . Or maybe just knock the barnacles them up and sell them for what they were, attended for. I should get them tomorrow, and I'll clean them up and see if there are any numbers stamped on them to get a idea what they might have come off of..... Tedd

 

Tedd, if your 55 is running good I wouldn't fool with it. Any gain you might realize would be insignificant. You can get into linkage problems and vacuum leaks. I have done too many of those things over the years. I tried putting a 56 carb on my 54 several years ago because a friend told me it was a better carb. It was a fiasco. I put a kit in my original 54 carb and it ran smooth as silk. Just my two pennies.

 

Glenn, car runs just fine, but I like a backup on the shelf just in case. Right now I have about everything but a spare carburetor. I'll probably never need it, it was rebuilt a couple of years ago, but it makes me warm and fuzzy to have it there looking at me just in case. Plus, I have the horder syndrome and as I understand it there is no cure....Tedd

 

If you want your Hydramatic to shift properly, you'll have to keep the linkage proper. I've got a 4GC on my '55 from a '56 Olds, and it works satisfactorily. The big change between "55 and '56 was the auxiliary throttle valves on the secondaries for those people who like to open all four barrels at low RPMs. If you want a backup, I'd look around for one from a '55 or '56 that's in good condition and rebuild it. Here are the model numbers for those used with Hydramatic:
1955: 7007000
1956: 7007221