If you're going thru all that get a 3.8. Or better yet, a 4.3 Chevy. I think Don and Curtis both are seeing high teens/low 20's. And the swap isn't that difficult or expensive.

Like Toasty said you may need a GenII SR. You'll get close to or better fuel economy then what you've got now. And, you could wheel it if you wanted to.

If it were me though, I'd keep the nice looking GenI and try to get all the economy out of it I could muster. It really sounds like you could be getting more out of it. I'm getting 16ish around town out of my LWB with bigger tires, bumper, winch, tools, and other weight gain stuff...