I am looking for some perspective please. My scrambler is a 4.2 jeep currently. I have a 4.2 with gm hei and howell fi with 10,000 miles in another jeep that I am parting out. I also have a gt40 302 small block ford. I know the v8 will have way more power, but I don't have enough personal experience with the 4.2 to know if it will really have enough punch to hold speed for highway travel. The transmission will be an ax15 regardless of engine choice. I will run a 35 inch tire with the new drivetrain swap. I am looking to hear from those of you that run 4.2s on the highways at 65-80. Chris