Exhaust Manifolds

Generally peak torque for the average street guy is 0.9 to 1.27 lbs-ft per cid, can go as 1.67 for a max effort race engine, most are lucky to get over 1.3, and for engine were talking about might get 1.15 to a high of 1.2 lbs-ft per cid.

So a 318 will make a peak tq of 280 to 380 (stock to fairly modded) lbs-ft and a 360, 330 to 430 (stock to fairly modded) lbs-ft as you see a modded 318 is a like a stock 360 under 3500-4000 rpms, you need rpm to overcome the difference with about 600 to 800 rpms more from stall to shift points, or during cruising geared to spin 600-800 rpm more at any given road speed.