The 53 series are governed at 2800 RPM, which still isn’t a lot but gives you around 1100 RPM power band. You can use the calculator on 4lo.com to calculate your gear ratios and rpm at any given speed.
I don’t think a 4-71 would fit. It’s 40 inches long and weighs in at around 1700 pounds!!
I’d personally go with a 3-53T. There are bellhousing a available to run an NV4500 behind one.
https://www.depco.com/resources/standard-engine-specifications/
