Those heads you speak of were probably one of the better heads in the 1980s before the Vortec head was introduced. Although not aluminum they were the cast iron version of the L98 head. They are real similar to the 217 head which was used on a marine application and a crate motor as well. Xtremefi is using those heads building 355 TBI engines. They are claiming they are making about 317-320 hp with them with a roller cam with like 209 duration@.050 and .455 lift. I don't have flow data on them but I can tell you they will definitely outflow the factory TBI heads easily and really make for a way better upgrade on a TBI application.