Not necessarily, but kinda yea:D
I run 80mph at 2,100 rpm's on the hiway getting a hair over 25mpg and can still light tires just fine.
1996 5.9 Magnum 9:1 carbed
214/224 cam
A500OD with lockup
15" 60's on the back
There's no way I can get into the cam power range in anything higher than 3rd.
In OD I would have to be doing in excess of 140 before the cam even starts building.