Ran a set on a 368" R1 in the car in my avatar - but they were the Batten aluminum version.
Low 10s footbrake @ 3000-ish lbs, with an 850 Holley that was basically a restrictor plate.
Intakes flowed 322 CFM, exhausts 248. 2.05 intake valve
Indy bought Batten out years ago & has their version with different valve seat/guide architecture.