I have the 40' version of your bus and LOVE IT!!!!!!! Look at my thread "Heavy Fuel". I intentionally went with a Cat engine. Yes, some don't like the Cat for various reasons, but I LOVE the Cat. Had three 3406B Cat engines that went well over 1 MILLION miles. Back in the day my '88 International 9200 had 1.3 MILLION miles WITHOUT a major rebuild. Did a cylinder head rebuild at 650K and she just kept on going. The other two I did a head rebuild at 800K and they went 1.2 million before I went belly up when Whirlpool left Indiana (another story for another time). Those engines went through hell and back more times than I can count. LOVE my Cat engines!!!! Put Prolong Engine treatment in the engine oil, Marvel Mystery Oil and Lucas in the fuel tank and PRESTO you now have a Cat that will go an easy one million miles. Change engine oil every month/10K miles and relax as the miles go by. I'm doing this with Heavy Fuel and her 3208 Cat engine as well. They replaced the engine with a Cat certified engine at 150K in California, so I now have a one million mile engine ready to run with. I know others on the site hate Cat (my pity to them), but when taken care of properly, they will last longer than the rest of the bus. Wife and I took nearly three years to find Heavy, but we're very grateful we did!
Hope this helps.
Firearms stand next in importance to the Constitution itself. They are the American people’s liberty teeth and keystone under independence. — George Washington