Big horsepower 318 builds

Think it's 706 heads. And I think they only flow like 230-240 cfm and they seem to get well into the 400's hp with fairly small durations like 212 to 226 but with .550-.650"+ lifts and fairly wide lsa 112-116.
That's probably the ones.....but I know zero about LS stuff and plan on keepin it that way.