You need more info on them Dart iron eagle heads . Sounds Like they have Heavy Roller Camshaft Springs . Yes you don't want them for a Street Engine with a Mild Hyd Camshaft . Is this a 5.7 350 OEM Roller Camshaft Block ? And are you planing to Run a OEM Type Roller Camshaft ? Also them Dart iron eagle heads have a different Bolt Pattern then Your G.M TPI Intake does . You will need to make some Mods to make it fit .