I live in Phoenix (~2000ft) and around town my tahoe works fine (not looking to "hot rod" it). Last weekend however, I went on a day trip to Flagstaff (~7000ft) since I'm looking seriously at transferring up there for my masters. Understandably the higher in altitude I went, the worse performance became. The vehicle has 4.56 gears (32" tires) but it was often hard to even maintain 75mph on many of the hills (5-7% grades) without downshifting and even then acceleration was painful. By the time I was driving home that evening, I was dead set on a turbo.

I don't see a need for more than 5-7psi since my objective it really to maintain HP/performance, not add (though I won't complain..... ). Also simplicity/maintainability/lifespan/cost are of high importance. I don't like rear mounts (turbos belong up front near the heat source) so they are not an option. My first "choice" is usually small-er twins (one on each bank) but since I'm looking more to maintain HP under steady state conditions (not fast tip in response), a single large would provide a lower air charge temp and more capacity overall (correct?). If possible, I would LIKE to avoid adding a cooler (at least initially), but I'm not sure that is really feasible.

How to go about it?

 

I live up in the clouds also. Turbo's work much better at altitude then superchargers. Go for it! Give Trick a call and he'll hook you up with a great setup!

 

i agree with him. Even my little 4.8 never downshifts. and I it pulls really gooded 4th gear TC locked at 70 too.

 

I've made that drive several times, don't recall my truck down shifting much, even with the 4.8 and t60 turbo unless I "needed" to pass some one . I think my base kit would work well for you.