The 1973 Ford emission crap slowed the Ford LTD to a crawl going up hill. Had to go in for service several times.
Look up the drop in horse power between 1969 and 1972.
Oh I know. I rebuilt several of Ford’s Emissions motors from that era.
They retarded the all cams several degrees, shrunk port and valve size in several engines and eliminated the 4BBl in all but the 460 IIRC by 79.
The fix on a fresh build? Strip the emissions, replace the cam with a pre 70 cam or even an Edelbrock Performer, add a 4BBL intake and a smaller 4bbl like a Holley vac secondary.
Swap the distributor and ignition with an MSD and without ever touching valves, ports or compression you are into solid HP/Torque numbers. Basic step 1 hot rodding like that will damn near double the mileage as well.
With a fresh build, 1.5-2 points of compression, headers and free flowing exhaust, you have even more of the good with zero downside. And mileage increases yet again.
My last build was the much reviled 400 ‘boat anchor’ done with all the useable Cleveland parts and the above basics in a 79 F250 4x4 W/Danas, C6 and a 205 case. It will light up 37 in Goodyears with no issue. 15 MPG highway.
Your point is well taken, you're not wrong. But keep in mind they started using SAE net hp figures instead of bhp figures around '71 - '72.