Found my dream truck but have a few questions

I went saturday and test-drove a 2003 Peterbilt 379EXHD. Has 10 virgin 11R24.5 tires, brand new seats and brand new carpet. Has the drivers lounge in the 70 inch sleeper with the fold up bed with the table that folds out from under it. Has an 18 speed and 3.55 rears and every gauge known to man. Also has the Cat 6NZ with 1.4mil and had an in-frame done at 700k so it has about 700k since the in-frame and had the turbo replaced about 200k ago. They want $62,000. This truck appears to be the real deal. Very well maintained according to the paperwork but I have a couple of questions.

Question #1: Will it cause a problem having 11R24.5 tires on a truck and 22.5LP or 11R22.5 tires on the trailer? I don't want to go down the road with the nose of the trailer up in the air and put me over-height. I looked at the 5th wheel and it does not sit as high off the saddle pins like my T660 company truck does. Could be a low-profile 5th wheel. I have been looking for 53x102 vans with 11R24.5 or even 24.5LP tires and they are very few and far between. If I can run 22.5LP or 11R22.5 then it will make my trailer search a whole lot easier. I do know that we have some trailers at work with 11R24.5 tires and our trucks have 22.5 tires and i couldn't tell a whole lot of difference standing back looking at the truck/trailer to see if the trailer was slanted up or down.

Question #2. I'm not very knowledgeable about CAT motors. My expertise is with Cummins and Detroit engines. I do know that the 6NZ is about the best motor CAT produced. I would assume it would be advised to do an in-frame about every 1mil miles like most engines. That would give me 2 - 3 years (if nothing major happens) before I have to in-frame it. For some of you who have CAT motors, especially if you have a 6NZ, how much would an in-frame cost on average?

I was a mechanic before I was a driver and I went over this truck with a fine tooth comb. Everything I saw looked excellent. I just don't want to have a problem with the tires being too tall for a trailer with 22.5's or if I get it and something major happens, how much will be forking out for the in-frame.

Thanks for the help guys!

 

Perhaps I should elaborate on why I "fell in love" with this truck. I want a pre emissions (at least pre DPF truck) so that puts me at 07 or older. I don't want an ACERT CAT so that that takes me to 2003 or older unless I find one up to 2007 with an ISX Cummins. I also want an 18 speed with 3.36 or 3.55 rears. 3.55 is ok if it has the tall 24.5s. If they were LP or 22.5 then I would want the 3.36 rears. I also want the 70 inch sleeper and it has both side widows and the escape door. The door and windows aren't a must but I do like having them. I really wanted the work station (drivers lounge) and this is the first pete I have come across in the past few months of looking that has one. It also has the full gauge package. Its not a deal breaker if a truck doesn't have the gauge package but with me having quite a bit of mechanical knowledge of these trucks, I like to keep my eye on everything I can.

With all of that being said, this truck hit every single "must-have" on my list that is in excellent shape. I have yet to find a truck that meets all of my criteria until this one. The trucks I have been finding either have all of what I want but they are ragged out and beat to hell and back or they are very nice trucks with high gears or flat tops or something that would be a deal breaker. Or, they are across the country and this one is 45 minutes from my house. My budget for a truck is $80,000. When I found this truck that had everything I could ask for in a truck and saw that it was $18,000 BELOW budget, I was very interested. After driving it, I fell in love. Admittedly, this was the first time I've driven a Peterbilt ever and the first time driving an 18 speed (I have driven 8/9, 10, and super 10 before). The 18 was just like a 9 speed with a super 10 up top and I love the super 10 trans so I felt right at home splitting the gears. That may have had a part to play in my falling in love with it.

 

Here is the truck in question. http://www.truckpaper.com/listingsdetail/detail.aspx?OHID=5251831&dlr=1&pcid=2000659565

I want to say that the trans was rebuilt when the in-frame was done. I can't quite remember for sure when it was rebuilt. I never saw anything about the rears and he never said anything so I would assume they haven't been rebuilt until I'm told otherwise.