Engine question- jeep/AMC engines

[Sappersoldier88]

Does anyone happen to have the answer of why any V8 from '71- to '72+ engines in jeeps (j-trucks, wagoneers, cherokees, and CJ's) Dropped 50-95 Horsepower and 55-80 ft/lbs of torque through the years?

I can understand it from an economical perspective because of the gas crisis and what not, however looking at specs online, there wasnt really a lot of change to the engine in terms of mechanics? If anyone could answer that for me, that would be awesome.

Im considering an engine swap, and just by looking at numbers and spread sheets, it seems that finding a 71 and below engine would be more useful than a newer model engine.

 

[uglyjeepoffroad]

My guess would be lower compression and smog crap.

 

[jds97Wrangler]

My guess would be lower compression and smog crap.

That is good part of what caused it. Another thing that caused the lower horse power rating was how they were rating the motors. In the 60's and first part of the 70's they measured the horse power at the mtor, today horse power and torque is measured at the tires.

 

[amcjeepman]

Horsepower prior to '72 was measured as SAE "gross" horsepower, the max an engine produced under optimum conditions with no accessories, In '72 it changed to SAE "net" horsepower which had more real word conditions.
See :
http://ateupwithmotor.com/automotive-terms/47-gross-versus-net-horsepower.html

 

[Sappersoldier88]

Thanks for the input guys, i kinda figured a few of those were the answer, but wasnt sure.