Should be fine, but the extra vacuum (250/292 = bigger and more efficient) may need the jetting adjusted down a bit.
I'm not sure how the Corvette manifold functions. As said, it came with Powerglide - not a very forgiving arrangement with low stall speed, and wide RPM drop on the shift.
If the YH is about 128 (I got that from somewhere?) and the Corvair 180 hp variant a bit more with its larger venturi (1-3/8" vs. 1-5/16"), they would be a bit much if used together in a log-type manifold (big open common plenum) with each cylinder drawing from all 3 carbs = 384 CFM. The drive test suggests that even though the 3 runners have connecting passages they may be pretty small and only balance idle vacuum.
Anybody ever measure the connection ID?
