We have done a ton of 400 and 440 strokers using 440Source....Great parts, great prices, and they all fit well. No complaints. For a 383, you can go to 496 and then as mentioned, put a fair set of aluminum heads on it.

We like the Indy EZ heads, and have made darn near 800hp with a set on a 400 stroker....Just an awesome combo. Don't skimp on the rockers or the pushrods though. The low decks have more angle than a 440 and really need a rocker that centers well in the hole....We used the Comp steel ones, and they are awesome.