Just remember that the present engine is left hand or runs the opposite direction compared to the 466.Would probably work with VR731 Allison, which has an added direction of engne rotation reverser. I'm not sure of the overall length or height though. I don't know if the work would be work the effort though if it fits. 6-71's are pretty reliable and get decent fuel mileage in that size coach. A newer turbo'ed engine would work well. One of the biggest concerns with a 466 would be engine vibration transmitted to the chassis. Two cycles are very low in vibrations. Get dimensions from 6-71,466, VR731, and the angle drive manual in the coach now and do the math. Installing a V730 automatic behind current engine will stick out of the pass side about 4 inches. Performance would be fair behind a na 6-71 engine; satisfactory with turbocharging.