Here's a good I-5 engine read if ya haven't seen it..

[Jeepwalker]

https://www.topspeed.com/cars/car-n...-engine-gm-s-42-liter-atlas-i-6-ar174949.html

A buddy of mine who competes at the Engine Masters (and usually places quite high) says he believes the Atlas engines could be built up to put out a lot more power.

My stock I-5 seems pretty powerful for what it is.

 

[Mr_Rich]

Good read. I agree about the Atlas engines. I remember my '86 Jeep Comanche with a 2.8L feedback carb'ed engine. Ran great and handled great but no power for carrying any kind of load. My 3T with 3.7L/ M5 actually does very well hauling a load and staying at the speed limit. If I lose momentum on a grade it does take a while to get back up to speed.