Imput on this KW900 with a 425 mechanical

Looking at adding a 2nd truck to my business gonna haul livestock locally in a 300 mile radius, got a relative I was gonna let drive my freightshaker and I would drive this one. heres what I've found wanted to see what you guys thought of this deal, any imput good bad or otherwise would be appreciated, thanks in advance.

1990 W900, guy selling is the 2nd owner and I've verified, yes seen with my own eyes actual receipts and paperwork on all work done. Paint is decent, however I've got a buddy that would paint it for less than 2k for me. Interior is pretty good, ac works good, all gauges work except 3.
This is the first truck in a while I've found that the owner has actually had the paperwork for work done. he said he paid 15k for it 3 years ago but with the work done in last 3 he's got over 35k in it. plus hes checking to see if I could buy an add on warranty when it expires.

whats the good/bad on this mechanical cat? mpg? can power be turned up and can anything be done to get better mpg out of it...he said he pulled 80k and got about 5. Only thing that has me debating is the it being a fuel hog, however I'm kinda leaning more towards wanting it because its a w900 and a ton of work done to it.

Heres specs

425 CAT - Mechanical
15 Speed 1 Million 40k miles
5 Months warranty left on motor (Aug 30, 2011)

Replaced with the last 3 years
- Front end
- Fan
- Radiator
- Clutch
- Starter
- Alternator
- 5th Wheel
- All hoses and belts
- Steering tires in great condition
- Drivers caps in fair condition

asking 11,000.

Thoughts and imput?

 

Thanks ya'll for the posts and feedback! Well it was a tough choice but I had to let the w9 go..right now I pull a bullrack with a 12.7 detroit in a midroof and average a good 6.7 mpg I've got a good tech that's a wiz on em. So anyways I just picked up a 94 kenworth t600 with a 12.7 detroit for 6500 all major stuff redone that im putting a 2nd driver in. My goal is to pick up 4 more trucks with detroits. I know alot of guys don't like em but if they tuned good they really add $ to the bottom line. Mine got 5.8 and couldn't pull but after my tech tuned it and found some bugs she gets good mpg and pulls strong if I put my foot in er on hills loaded alot of times
I don't have to drop a gear.

Maybe one day ill have a cat..if its one with a ecm mr haney could reflash or I could throw a bully dog on to get into the 6's.

 

Thanks les...I don't remember who said it but someone mentioned for every 1/10 mpg better u can average its an extra 1k a year saved..pretty huge imo

 

nope no bankruptcy for me bud...i've got more livestock to haul than i know what to do with (not affected one bit by a recession, bad economy), i pay cash for my trucks fook the banks and high interest, i've got guys wanting to drive for me, have virtually no overhead, every truck will gross 200k a year, I do believe that is more than enough to take care of fuel, pay a driver and make my pockets fat.

a guy would have to be a pretty big idiot to screw up the position i'm in. I will be managing this business from the house and not have to drive day and night for the next 20 years. I'll only drive if I WANT to