Theoretically, from 2.375 to 2.17 (.030 under stock 2.2 bbc) is a possibility, so.minus .205. Id offset as little as possible to get to 371". Then you need to find a bbc rod you like, and custom pistons to fit.
(I'd use B1's, have pistons made for them, use the B1 intake, single four, blow thru 4150, and a big single turbo. )