Whats the difference between 4.0. and 4.0 H.O

Jeep has 4.0 and 4.0 H.O. What are the mechanical differences. Horse power?

I guess i could google horse power…

Sounds like a plan to me.


What makes an H.O. an H.O. is it that blower sticking out of the hood

A slight redesign in 1991 led to an increase in horsepower.

A “blower” sticking out of the hood?
“Blower” usually refers to a supercharger, and I have never seen a factory-stock Jeep equipped with a supercharger.

Perhaps you are talking about a hood scoop, but a hood scoop is not necessarily an indication of anything other than a styling affectation. Cars with a turbocharger or a supercharger will usually have a hood scoop, but I could probably come up with a fairly extensive list of vehicles without a forced induction system that also have a hood scoop–such as some Jeeps.

I was just screwing around…to much time on my hands

I understand that but whats different about the high output That is whats mechanically different

The H.O. engine had–IIRC–larger valves, larger intake passages, and improved injectors.
Possibly, it also had a higher-compression cylinder head.

That helps…Thanks