I've been seeing pretty similar to you. Rebuilt engine, SC w/ 2.8 pulley, intercooler, 5.29 gears, and 37s. 13mpg - high 14mpg (freeway).
I no longer daily drive, and when I take it to work it's freeway/open roads.
It's not to difficult. Gets easier each time you do it. Took 12 hrs the first time because I also changed the crank, oil, and water pump seals.
Additionally, the instructions are easily assessable online.