[Neweller]

Keith, I obtained some great information. May not be what you want to hear but I got the info. The 8.3 Cummins would work but it is basically just a notch up on the 5.9 Cummins. The 8.3 would definitely be an upgrade to the 555. The mechanic said that he always recommends going with the largest capacity engine you can make fit comfortably so the engine will not work as hard while helping it get a higher MPG. The 8.3 would be fine up to about 35' coach, after that it will be under powered unless cranked up and that would take away from longevity and MPG. Gears are not a real big deal to do if needed. Most gears run around $600.00 for a good used set. He said the only buses or coaches he is aware of where the gears get pricey is on the old Eagle buses where they can cost up to $2000.00.

Gear ratio's in these Newell's can be 3:33, 3:36, 4:10 etc., depending on engine hp and transmission configurations. Yours being a triple nickel and lower horsepower I'm thinking you could have around 3:36 and that is a wild guess.

The more I research the engine upgrade option possibilities, it really gets me pumped. This is truly the way to go and the more Newell's upgraded the better they should retained value. This is my serious assumption of course. Keep these baby's going for years while obtaining great performance, mileage and dependability.