Thanks! I have been playing with this idea for about 10 years, actually thinking about it since the 1980's (school bus conversion). I have spent literally hundreds of hours researching, asking questions, measuring, etc...and finally think I found a solution that will work for me. The auto tran is pretty necessary because some of my (hope to be) travel companions can't handle a stick. The OD options reduces wear on the engine, makes driving a vehicle less stressful, aids in holding the bus at certain speeds without using brakes and increases mpg a little. Also, from what I understand, the 8.3 and 3060 combo provide more than adequate power for a bus at any cruising speed on any interstate in the US or Canada and have power to manage the hills as well. The cost of a new transmission (I am guessing $5K or more)maybe will never be recovered by savings in mpg but the other benefits make it worth it, in my opinion. I was really hoping to use a 6bt because of the lower price of hardware, but when I started mentioning 65, 70 and 80 mph, most people on forums suggested that I look to something with more umph.
Based on what I have read/heard, a good 8.3 and 3060 should easily last 300,000 miles without problems if well maintained, cruising at interstate speeds. Most mechanics I talked to thought that a 6bt might start to show its age at around 150,000 miles. I would still love to find someone who would be willing to put a 6bt into a Chevy suburban for me...that would be a really sweet, durable deal also.
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