need info on a v8 swap

[crazyranger]

I have a 2000xlt 4x4 3.0 ranger. Im considering putting in a 5.0 from a 1997-2001 explorer or mountaineer. My setup after swap 5.0 swap will be, 3in body lift 4.10s and 33s < cosmetic. On the motor k&n cold air intake, throttle body spacer, some kind of preformence chip, and a flowmaster. Now the main reason im doing the swap is that i have a 18ft bass boat 150hp on the back im around 3000 lbs. I want the power to trailer, But if the 5.0 and this setup is going to kill my mpg Ill just conider a 4.0 swap.My mpg now with 3.73 31s is 15 city 20 highway. What mpg would you except to get with the 5.0 setup? Is it worth it?