I don’t know anything about the EFI swap, it might be marginally better, but I doubt it would be that much better than a well tuned carb. Problem would be collecting the computer, wiring, sensors, and retrofitting to a vehicle it was never on. I imagine it would be similar to a Howel injection system on the 258. But, GM did feel it was better and used it until the mid 90’s.
I would either drive it as is, or swap in a SBC or a 4.3 v-6.
My ‘82 was originally an Iron Duke. Previous owner swapped in the 232 from a 79 Spirit. He only used the Jeep around his property near cottonwood, az. If the 151 was underpowered for just running around the hills in Arizona, I can’t imagine it would be much fun on a highway. City street should be fine. (I’ll bet my original engine is still in the barn of the original owner. Wish I had grabbed it when buying the Jeep.)