A Banks kit for a motorhome 460 ford had 50 inch primarys in the 4 tube headers. It was amazing how much better that rig pulled. The claimed torque increase was 87 ft lbs, as i recall. And it had every extra one. It would be great to see just what that would do for your 541.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky