Tuning with jets, Power valves and an O2 guage

Yeah, but I have considered removing it. If the engine performs as I expect it to after the I get it back together, I may switch from the 3.91s to 3.23s or 3.55s and direct drive again. I got almost 11 mpg with 3.23s at freeway speeds in 2011. I do most of the driving locally anyway.
There has been a slight vibration since the install. It is probably because I didn't cram it up in the tunnel high enough and the driveline and U-joints aren't aligned properly. I'm sure that there is some parasitic loss associated with it too. I kept my stock tailshaft and drive shaft in case I didn't want to keep it.