Dug out the old XLT monoblock. All 3 are in good shape, no dry rot or anything. They were however laying against the inside of a plastic bin so a little flat spot on 2. Nothing a little warming up won't fix. I don't have the clamps somehow. Here's the measurements:
"rib" to "rib" (the part that "holds" the carb into the boot)
And "inside" of boot:
These numbers may be slightly skewed as the boots are a little deformed.
Lemme know if they'll work.
Man I love autoupload to dropbox. Makes posting pictures so much easier.