It's not the engine HP that counts. It's the energy management that counts. Heck, even gliders do aerobatics.
Just take your time, climb high, dive to the correct speed for your maneuver and do it.
It will probably become a problem in competition aerobatics though, where you've got about 3000 feet to complete your sequence in.
Also take a look at the W&B sheet. A lot of aircraft have tighter limits, and a lower MTOM when performing aerobatics.
(And the usual caution: don't try this without a qualified instructor.)