110K Mile Tune Up and Mods

I recently bought my first Tacoma (2004 reg. cab, 5 speed, 4x4) and I am preparing to do a thorough tune-up and perhaps some performance mods. I am looking for some seasoned owners to chime in here with any tips, advice or suggestions about what I have listed, or what I have not listed. Any input is appreciated.

Performance Mods:

air filter deck plate mod

relocate breathers

add a transmission cooler (and an oil cooler?) -- I live in the mountains and tow 2500-3000 lbs on occasion.

a header?

??? Any suggestions ???


Here is a list of what I plan to for tune-up:

Fluids (trans, tran case, front/rear diff) ... should I drain the trans or have it flushed? Does the trans have a filter to replace? I plan to refill with high quality synthetic. (Brands?) The manual says to put "Hypoid" GL-5 in the diffs?

Change Spark Plugs (Denso?), inspect caps and wires.

Lubricate hubs, inspect brake pads/rotors, inspect and lubricate tie rods and u joints, drive shaft, propeller shaft

clean intake and throttle body

Flush radiator?
Change fuel filter?

replace bad rear O2 sensor


Thanks for any help!