[N80]

The 3400 will provide enough hp for a 5' medium duty no problem. What you need to look at is the weight. Look in your manual and find the implement weight guide. The max weight your tractor can handle is significantly less than the 3 pt lift spec at 24" inches behind the lift point. In other words, on my L4400 the spec is something like 2000 pounds, but the max recommended implement weight is 880 pounds. This is because with something like a mower that weight is cantilevered way out back. Some folks suggest you can go higher than that recommendation if the tractor is ballasted properly. This may be true, but I wouldn't exceed it by much.

Anyway, see what your manual says and then look at the weights of these medium duty mowers. If they're close, then go for it.