Originally Posted by sshhaammaann
Why would you recommend against a gm 5.7?
Having had a 5.7l tbi and vortec in full-size trucks, they are OK for what they are, but even with 4.10 gears seemed to struggle with a load behind the truck (which, compared to the aero of a bus, is streamline, so the lack of hp/tq will be more significant).
The 5.7l engine was GM's bread and butter and if the price were right, and you had the ability to swap in an RV cam, some heads (vortec on a tbi is a good, cheap upgrade) and some headers than it wouldn't be all that bad.
My recommendations were mainly focused on reliability, and out of the box performance. If you are ok with plugging along at 55mph and still getting 8mpg than a 5.7l will be fine, if you want to keep up with traffic, some of the more modern mpfi engines with standard overdrive automatics would be my preference. Not to mention, the Vortec only existed in obd2 equipped vehicles for ~5 years....when it comes to roadside diagnostics, I prefer an obd2 equipped vehicle over the alternatives.