I stroked my 383 to 496. With exhaust manifolds. Lightly ported stealth heads, not so big of a cam, with an lsa of 114, to match the manifolds, rpm intake and 750 hp holley, this made nearly 450 rwhp and 470 rwtq! Like I said, this is a mild build, haven't took it down the track yet, but it should run in the high 11s