Aftermarket carb for 273 commando

Hey everybody, i, just today I have become the proud owner of a 67 valiant with a 273 commando. It runs well (as well as it can with a carb that floods it out and frozen jets on said carb), and a leaking timing cover.(gasket already sourced thanks to felpro) and have come to a minor problem sourcing an aftermarket carb to fit the stock intake manifold. I'm not looking to hotrod it, just find a decent 500cfm carb that'll fit. Beautifully solid car other than those 2 issues. Does anyone know where I can find a carb that fits, complete with model number? I have checked jegs, summit, and rockauto to no avail. Please help. Thank y'all.

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