Back in the 80's when I drove my Hemis quite a bit they seemed to like a quart about every 1,000 miles or so. Loose pistons, so-so gaskets and valve seals I imagine were the cause. No way I ever used a quart of oil per tank of gas however my friend Bruce had an LS7 crate engine in his 67 Corvette and it did use a quart of oil per tank of gas.