Answer to "Compatibile with Detroit 12.7"Cliff is the man, good advice and info from him ALWAYS. I also purchased a Columbia glider and yes scan gauge is compatible. With your ecm port being located on the rear of the drivers door you may need to extend the length of the cable that comes with the scan gauge depending on where you wish to mount it. A cat5e cable and connector will do the job. I Had to go to Best Buy for the connector, Not many stores carry them but they are available everywhere online if you want to go that route. Yes the MK is the "generic" version of the Series 60, but still a decent engine. The MK is the 430HP version and the MP and MB are the 500HP version. There re differences in various parts, but overall, you will do fine with the MK. Extra power would be nice with the 264 gears matched up with the 10 speed, but you'll definitely still be a couple steps ahead of most Volvo's out there when it comes to getting up to speed. Good luck.
Answer to "does fleet have a filter for the peterbilt 579"Wow, I can't believe no one has helped you with this question. I'm positive FAF makes an air filter for you. you can go straight to their website and check. Mine was the same number of the paper filter that was being used, 3518. I'm sure you could call FAF to see if you can't find anything on the website. Pittsburgh Power also handles FAF and they could help you also.
Answer to "6NZ or Series 60"I have heard Kevin say multiple times on his show how much he loves the 6NZ. The 6NZ , N14 Cummins, and Series 60 are his favorite engines, Pre EGR of course. Good fuel mileage and dependability to be had with each one. Personally, I'd go with the 6NZ Since it's in there, less hassle. You'd need a new ECM for the series sixty, the cost may be more to switch over.