[JayJay]

My pickup came to me with a Tillotson, and indeed the top and bottom halves do not mate properly - more than 0.025" gap. It appears that the warp is in the top half. For now it's running OK, so I'm not inclined to mess with it too much, but I have a bunch of Zeniths around and I'll eventually get around to building one good one and installing it. (Tyler, for your background, the Model A came with a Zenith carburetor. The Tillotson was a popular aftermarket replacement. If adjusted properly, the Zenith is a fine and very robust part. I don't expect that today many of us here on the forum would preferentially install a Tillotson over a properly functioning Zenith. If you elect to replace the one you have, 1crosscut had a great idea to contact Steve Becker at Bert's Model A Center in Colorado, he can set you up.)

I've had success with flattening mating surfaces by taking a granite plate (or a piece of thick plate glass), attaching a piece of 220 grit wet-or-dry to it, and gently moving the part across the paper. Rotate the part 90 degrees about every ten strokes or so. Don't press down hard on the part or you will unconsciously slant the surface - it may be flat but not necessarily aligned properly. I do this as a matter of course to things like goosenecks, carb upper mounting surfaces (to the manifold), etc. It's difficult to do with upper carb bodies because of the things that protrude down like the float mounting bracket.

For parts that are too big to move (like the upper gooseneck mounting surface or water pump mounting surface on the head) you can use a large sharpening stone, available at most hardware stores.

I agree with Jerry Kzoo and Y-B, though, that if you're pouring gas out then you have a float height adjustment issue as well as a mating surface issue. The float height adjustment issue is the more critical at this point and needs to be solved first. Good for you that you're diving in to try to solve this, that's how you learn.



JayJay