408 Stroker in a Dart

Test #3, #4 and #5 in this link kind of shed some light on this - https://www.hughesengines.com/TechArticles/8408416strokerdynotestingsept2002.php

Looks like the cast iron intake and exhaust (with some work) gave up 56 hp and 45 ft/lbs to headers and an Air Gap. But even then, the cast iron test isn't too bad with 447/471. Now on the motor the OP is looking at, maybe he is down 50 hp? Up to him if that is giving too much up.