The hemi is a large engine for sure . I was able to add some items under the hood , catch can, switch pro . I could have mounted the ARB dual compressor but chose to mount that in the spare jack area. I think the kits out now have solved the "cooling" issue with the hemi. I live on Oklahoma and the summers here are stupid hot. i have not had any cooling issue . the kit came with a JL fan and heavy duty radiator. I swapped in a 180 degree thermostat ( ran a 180 thermostat in the 3.8 too) . I can run the AC on full blast and the engine runs cool. I do agree that the newer LT engines are high speed and offer a packaging advantage. The only "concern" I might have with the hemi is the alternator location. Its low and not easy to access. i would prefer the 6.4 accessory drive off the 2500 ran instead of the car accessory drive. When it comes to selection of a kit and drive train I would not mix drinks , stay with one manufacturer. Go all mopar or all chevy . when it comes to any maintenance or trouble down the road you would have an easier time with troubleshooting and parts availability.The hemi is physically large and quite a bit heavier than an lt engine and lower tech. It might integrate easier, cooling would be more challenging also with minimal real estate under the hood. I would hate to ruin my jeep with any poor conversion. Lots to think about with any of these 8 cylinder conversions.