You can get a 3.58" crank that has 340/273 main bearing diameter. Eagle, Molnar, and Scat all offer them. Heck, if you're feeling froggy, Molnar has a 3.79" stroke crank. It has SBC sized rod journals though. As
@toolmanmike mentioned, pistons for a stroked 273 might be "fun" trying to find. Heck, 273 pistons for the stock crank are kind of an issue unless you're happy running Egges.
