This stock 6.0l LS with cam and headers made 514 @ 5,900 rpm and 493 lbs-ft @ 4,400 rpm so 1.35 lbs-ft per cid. Cam was only a 228/230 on 112 lsa so obviously the stock heads and intake work well a bump in cr probably would get closer to 1.40 tq:cid. Similar peak power and rpm as the 371 and 408 but like the 371 under the curve is a bit shy.