You should have come here and done your homework first. We would have advised against any bus newer than an 04 due to EPA regulations that are hard to diagnose and expensive to repair. The DT466 you have is a good motor, not as good as the 04 or earlier ones. The important factor on road or highway is the transmission. A 545 is normally not desired, but some say they are okay in a short bus. Any other trans would eb good on the highway, depending on rear gear.
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