My Kubota was a B7800. It was a great tractor. Only 30 hp but good hydraulics. Never had a lack of power but sometimes needed a little more weight for traction. I think I would try the L3400 if I had it to do over again.
Hmm, maybe something is wrong with your 3038e then. Kubota lists the loader for the B7800 as having 1684lbs of breakout force at the pivot, and JD lists the 3038e as 1704lbs at the pivot. Not to far off from each other.