I am really needing to do something about the Y block in my 55 Customline. I am getting ready to set it up to pull my Avalair trailer. I want the power to pull the trailer, but I want reliability. I am at an age where the wife has endured 30+ years of projects etc. She's ready to travel in the 55. Who am I to argue? She says source a new powerplant for the tow car, so I am looking into my options. 1. Rebuild the Y-Expensive overhaul- Would require an adapter for the OD transmission-Very little modification to retain, Parts availability on the road limited 2. Replace with FE 390 -Expensive overhaul- Would require an adapter for the OD transmission-Parts availability on the road limited, gas mileage is minimal. 3. 302 Roller motor-Better gas mileage, reliable- Less grunt for pulling trailer-AOD will go behind it with no adapter, Parts are more available 4. 351W Roller motor- Average gas mileage, reliable- More grunt for pulling trailer-AOD will go behind it with no adapter, Parts are more available, Takes up a little more space, exhaust is an issue. This is just some of the ideas bouncing around in my ADHD head. Thoughts?