That certainly is not made for the Chevrolet 250. Whether or not you can adapt it to fit would be hit or miss (probably miss). I never knew of Clifford making an intake for the Pontiac 6s.
Whatever the application, I seriously doubt the runners of this intake will mate up to the Chevy 230/250/292 heads. If somehow you can make it work then you could possibly have exhaust headers issues, and may have to fabricate your own headers.
I have the Clifford water heated intake for the Chevy 6 and it does not have divided intake ports as this one does. I'd say just save up and get the right one. You won't regret it.
-magic mike-