1 Answer

The most cautious is to keep it at the standard discharge
height, which is usually three feet or so above the floor
the washing machine is on. It is fairly common to raise
the outlet 3-4 feet above this level, however this does
entail some increased risk of pump burn out. The exact
degree of risk varies with each machine and the conditions,
and the only way I know of to determine it is empirically,
i.e., trying it and seeing if the pump burns out.
Your pretty close to being within the range people commonly
risk. Perhaps you could make a raised area for the machine
and the person loading it, and/or slip out as low as
possible under the floor level. Use at least 1" PVC pipe or
flexible PVC hose, include a swing check valve near the
machine, and a vacuum breaker if the line runs downhill
once it gets outside. If this is the case, you can locate
the vacuum breaker outside at the height of the machine
in the basement, and once the machine gets the water "over
the hump" it will get a siphon assist.
Hope this helps.

Source >>>http://www.oasisdesign.net/faq/gwWashMachPump.htm