I know this question must get asked a lot in various forms, but I haven't seen it addressed this way (just did a search). I live at 4500 feet above sea level. I own a 1991 3/4 ton Suburban with a 350 gasser, auto, and 4.11 gears. I tow a 6500 lb, 25-foot trailer at elevations ranging from 4500-9500 feet.

There is a really cherry 1992 F-350 Crew Cab with a 5-speed and ATS stickers on the fenders. I peeked under the bumper and didn't see an intercooler. ...nobody home to ask about it.

My Suburban is so slow it can hardly get out of it's own way. I can tow the trailer fine, but it isn't pretty and I slow down over every overpass. Mountains? a crawl.

Naturally-aspirated engines lose like 10% power for every 1000 ft elevation over sea level. Turbos don't have that problem, right?

So, if my gasser is rated for 190 hp/300 ft-lbs at sea level, I'm probably getting something substantially less at altitude. The 94 Turbo IDI 7.3 is rated for 185 hp/395 ft-lbs at sea level, and should get that regardless of altitude.

I said all that to ask this: Wouldn't there be more of a difference at altitude than the 95 ft-lbs at sea level?

I love my Burban, and have spent lots of time keeping it running. ...but I long for more power. Would the IDI with ATS turbo make me happy?

 

Simply put, YES. I love mine.

Judging by the info you provided (not that its new to me) the answer should be YES.

 

Have you thought about a blower for your burb? If you live at 4500 ft. You might be able to get away with running 87 or 89 octane and the price might be similar to buying a new truck.

Try calling a couple of the blower outfits and asking some questions. They could also set you straight about the turbo-diesel.

Remember also that as elevation goes up, oxygen content goes down. Even turbo-diesels run less efficient at altitude, just not as much as N/A motors.

If you want to pull and pull fast then a turbo-diesel is the only real choice. Big block gassers also pull good, but gas mileage will be 6-10 if you are lucky.

You could also try adding performance goodies to your burb. But you have to remember that a 350 with an auto stuck under a 6500lb suv, hooked to a 25ft trailer has a lot of work to do.