Just finished a 383 also with the Lunati 60302 (262/268 220/226 @.050 0.475"/0.494") Happy so far, break-in went fine, idles at 800rpm. No ticking lifters like I have heard on the comp XE series.
How much vacuum are you pulling ChrisF? I'm getting 15" and a cranking compression of 145psi, seems a bit low to me?