I have an 88 4.2 with the carter 2b carb.  Jeep runs great.  Idles perfectly and runs very strong in lower gears.  When I bought it the timing was too advanced and the engine would ping.  I retarded the timing and did the TFI upgrade which allowed me to then advance the timing a little still avoiding engine ping.
I have never owned a 4.2 but had a 4.0HO in college. Both Jeeps had 33x12.50 tires and factory gears. The 4.0HO would run about 80-85mph but my 4.2 that I currently own will only do about 70mph and will not hold speed in fifth gear. Is this normal for a jeep with this setup and with the tire size I have or do I potentially have a problem somewhere. I hesitate to do anything because it runs so well. Any ideas or suggestions.
				
			I have never owned a 4.2 but had a 4.0HO in college. Both Jeeps had 33x12.50 tires and factory gears. The 4.0HO would run about 80-85mph but my 4.2 that I currently own will only do about 70mph and will not hold speed in fifth gear. Is this normal for a jeep with this setup and with the tire size I have or do I potentially have a problem somewhere. I hesitate to do anything because it runs so well. Any ideas or suggestions.
 
	 
 
		 
 
		 
 
		 
 
		