Well I am wondering if anyone may have an idea as to why or even that the 3.8l had cast iron cam, crank and piston rods? I am doing my first ever engine rebuild and can not believe what I see. Could this be part of the reason that it gets dismissal gas mileage? I know that its a jeep, so I do not expect to see 30+ mpg's. So at this point I am going to replace all 3 for sure even with the low budget.