I've looked at stroking a 383 for a while. What stroke are you looking at to get 450 ci ? The 400 with the std 440 crank comes out to around 451 ci, the 383 with the same crank ranges from 431 to 438 depending on std bore up to .060 overbore. There's another option that's basically the equivalent to an offset ground 440 crank which results in approximately a 470 ci motor. Muscle Motors sells the 470 kit which seems like a good compromise perhaps, especially since to me a 431 'stroker' seemed a little small to me especially for a big block. I'd be interested in knowing what you decide on because until I start my 440 stroker build I'm still open to other options. My Roadrunner has the Airgrabber setup so I have had to pick intakes that are the std height. I have a mopar M1 dual plane intake on it now which is basically an aluminum version of the stock iron intake. I've read that the Weiand Action Plus intake is another one that is almost exactly stock height and painted looks almost stock. Good luck.
Later, Jim