[AnthonyG]

Not an issue X2. Several reasons it’s not. The crack doesn’t break out at the fuel intake ports or the edge of seating surface, so even if it does enter the surface deep enough to break into exhaust as Terry,OH speaks of the carb gasket will seal. If your a belt and suspenders guy like me, I’d put a thin layer of high temp RTV on it & install / tighten gasket & carb while wet & let cure. No potential for any leakage of exhaust or vacuum & an invisible fix.