Downsizing a good thing or bad

[case245]

I thinking bout trading in the M7040SUD FOR A M5140 hydro shuddle a few reasons the 7040 is manuel im tired of shifting and I want the assist cylinders on the 3pt is the 148 cu in engine in the 5140 going to be to small I was pulling last eve on the 2nd pass the 7040 was grunting even at 2000rpms in 4wd pulling 3 bottom 16'' boards so is the 5140 going to be able to handle that task or is it going to stall I also drag logs with my tractor I don't know if it will handle that my 7040sud has a 203 cu in engine