In 2011 for EMC I built a 371 (.060" 360) that made 513 ft/lbs 1.38 tq/ci 532hp on pump gas with teeny tiny EQ iron Magnums that at the time only flowed 267-272 cfm . IMO I made them a bit too big in the bowls. Weiand X-celerator manifold/750 XP. That engine was surprising for what it was. When I was done with that engine I made the heads bigger for 292-300cfm and used them on a 416--made 564 ft/lbs 1.355 tq/ci----Port speed was always just way too fast but I only needed 6500 rpm. Those heads just work. J.Rob
p.s. Every EQ headed build I've done , I've been told the engine is pure majic.