Some basics first;
1990 YJ, mostly stock, 4.2 liter, 5-speed Puegeot, 3:07 axles, 31" tires, no lift, engine runs great- doesnt leak a drop, doesnt use any oil, 120k original miles.
My Jeep starts and idles fine. Its been nuttered, and I still run the Carter factory carb. I can drive down the road with plenty of power, as long as I am under 55mph or not reving too high. No issues with power or torque whatsoever under ~2200 RPM. I can hit ~3800-4000 RPM briefly like in first or second gear with decent power. The redline for my engine seems to be about 400 rpm, according to the factory tach. Its not that it wont rev higher, it just doesnt like to or seem to make any power at or over 4k. On the highway, I can hit 65 easily, but not much over no matter how hard I try. In 4th, 65 is around 2500 RPM, and I run out of power to go faster. In fifth I am only at ~2000 RPM and its not turning fast enough to make power to remain at 65 or above.
I do understand that aerodynamically- Its much harder to achieve higher speeds in a wrangler. One thing I notice is that if I run it hard- like accelerate hard to ~60, or if I drive much over 60 for any period of time, I get an awful smell from the exhaust. I can also drive anywhere (winter/summer it doesnt matter) and not run any hotter than ~210 according to the factory gauge BUT If I am on the highway, A/C off, it will hit well over that anytime I try to drive over 65 for any period of time.
Im thinking the smell is the converter getting hot. The restriction may be causing my higher engine temps when the converter is expected to flow any more than ~2200 rpm for any period of time.