6066 (1960-1966) GMC Truck Club

6066 (1960-1966) GMC Truck Club (https://6066gmcclub.com/index.php)

- GMC V6 and V12 Engines (https://6066gmcclub.com/forumdisplay.php?f=9)

- - 1904 Holley (https://6066gmcclub.com/showthread.php?t=50301)

I am looking for a new replacement carburetor for my 61 3/4 ton GMC 4x4. Any body have any suggestions?https://uploads.tapatalk-cdn.com/201...11638a2729.jpg

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Welcome Wrknman, nice truck you have there and the cool hood too.
Is the old unit not rebuildable? You an post a a WTB in the classified section.

Thanks. It is a pretty cool truck. The body is warped and will not seal to the bowl. I actually found another close ,but it was worped also. Must be a common problem.

That is the carb I have in my '60 3/4.
It is the one that came in the truck and I think I have rebuilt it twice in the 48 years I have had it.
It is a one hour job and will give you 10 MPG at 2MPH in granny or at 55.

Not familiar w that carb as I have the WW on two barrel intake. Could you replace your early single barrel intake to the dual and find the WW or even convert to the Holley? Maybe that’s something you don’t want to do? But it’s an idea if the 1904 isn’t that reliable?! My 2-cents

I must have to admit it has been too long since I rebuilt one of those so I do not remember if the offending part lends itself to filing it. On carb parts without interfering projections that prevent it I have taken a file and carefully filed it flat again. This is caused by inexperienced mechanics tightening the screws too much,

Over tightening or neglecting a sensible tightening sequence of the float bowl cover screws can warp it slightly and cause a pesky leak.

I have found this to be a very common problem with these carburetors. Next to impossible to find a used one that isn't warped at the float bowl to body interface. Seems that the carb body warps more than the bowl.

I have trued up a couple of mine using this method: Place a suitable flat piece of aluminum, 3/16" or so, over the carb body where the bowl attaches. Place the carb body in a large vise so that the vise gently presses against the flat piece of aluminum. Place a block of wood against the opposite side of the carb. Notice the areas where the carb body is warped (not flat). With a propane torch, carefully heat the high spots and gradually tighten the vise. Continue going around the edges of the body with the torch and slowly tighten the vise until the body lies flat against the aluminum. You may not get it perfectly flat but it should be much better. Careful with the torch or the pot metal could melt. Allow it to cool. When fitting the float bowl I have also had to enlarge the screw holes as needed to get the screws to line up with the threaded holes in the body.

I see that Permatex has a fuel resistant gasket sealer which might be something to try, along with a slightly thicker gasket than originally used.

If you get the surfaces relatively flat, I definitely agree you should only tighten as little as possible to stop any major leaking. I would be content with a slight weeping, which is what these did when they were new anyway.

I'd convert manifolds two the 2 barrel and install a 500 cfm holley 2 barrel. More power for the mileage you get. :thumbsup:

I'm only finding the rebuilt holley 1904's used on Ford's and Internationals. Jetting may or may not be different.