383 and 440, 383 + .030 pop up pistons 0 deck height, 67 stock heads, a ton of compression, 509 cam, torker intake 750 DP. Ran 7.0 1/8th. 440 dead stock (74) low compression, 452 heads with a little bowl cleanup, same cam out of the 383, torker intake 750 DP best was 7.59. Same adjustable rockers on both, same stock (spacer) electronic dist and MSD 6, same coil. 3800 vert and 4.88 gears 14-32 slicks on both cars. Now 383 was in a Dart and 440 in a 64 all steel Savoy. Maybe 200 lbs different
My conclusion, you can’t beat compression.