Thinking about buying an old wal mart truck

We have been thinklng about adding another truck to our operation lately. Looking for something lightweight, that I can will be able to hit 7 mpg with running around the northeast and midwest pulling stepdeck, liquid tank and end dump. Came across this truck and being we already have one IH cabover it caught my eye. '98 9800 International, flat floor single bunk with a 12.7L detroit, 10 speed direct and 2.81 gears. It has 800k on it. I have heard good thing about walmart's maintenance program from these years. The one thing that has me concerned is the rear end gears. My 9670 has 3.55s in it and our 379 has 3.70s. If I did get this truck, I have an 18 speed I would like to put in it. The 10 spd that is in the truck now has a 14.78 low gear and my rtlo18918b has a 14.40 so it should be low enough. Anyone with low rears ever take them off road at all? We are on road mostly but do get into contruction sites one in a while. I have already talked to rebel127 about doing a tune on this engine as well once I make sure it is mechanically sound. Any input would be appreciated. Thanks

 

My main reason for wanting the 18 is for gear selection on the hills and so there isnt such a big jump between gears when getting rolling. I know the 10 will get the job done, bit I think it will be less wear and tear with a few extra gears. I will most likely run the 10 for a while and see how I like it and then go from there. Thanks for the replies.

 

Why do you say that hhss?