Okay, this is just me thinking right now. I have a 91 rcsb Z71 that I would like to see get makeover. I have had the truck for about 10 years now and it is just sitting not being put to use. I am thinking about selling me Jeep cherokee and putting some money back into the ol truck.

What I am wondering is if I sell Jeep which is getting about 20-23mpg then what are my options as far as an LS engine to get decent mileage. I have way too many vehicles and don't want to get rid of the 91 but I don't like the throttle body engine. I know it would be cheaper to just buy a newer truck. I do have an 03 HD2500 crewcab 4x4 that has the 6.0l so I do know a bit about how it performs in the big truck. I would like to see a 6.0l in the 91 but I am sure mileage wouldn't be that great. So would a 5.3 or a 4.8 be a better option. This truck would be a daily driver that I would use to do all my personal running in and also use for doing my estimate for my floor care business. What are your thoughts. Thanks