N95UP WAS MAKING THE FIRST FLT AFTER BOTH ENGINES WERE OVERHAULED. THE OWNER OF THE OVERHAUL FACILITY WAS THE PILOT AND THE PASSENGER WAS THE FOREMAN WHO WAS RESPONSIBLE FOR INSTALLING ENGINES. A WITNESS WHO IS EMPLOYED ON THE AIRPORT HEARDTHE ACFT TAKEOFF AND SAID THE ENGINES DID NOT SOUND RIGHT. HE FOLLOWED THE SOUND OF THE ACFT AND THEN SAW IT NE OF THE AIRPORT HEADING TOWARD THE MIDDLE OF THE N/S RWY, THE ONLY RWY AVAILABLE. THE ACFT WAS AT LOW ALT WITH THE LEFT PROP FEATHERED AND LANDING GEAR DOWN. WHEN THE ACFT WAS 1/4 MI FROM RWY IT HIT A 50 FT TALL PINE TREE, ROLLED INVERTED AND CRASHED. VMC WITH STRONG, GUSTY SURFACE WINDS PREVAILED AT THE TIME OF THE ACDT. ACCORDING TO THE OWNER'S MANUAL THE SINGLE ENGINE RATE OF CLIMB WITH GEAR UP AND PROP FEATHERED AT 2500 FT PRESSURE ALT FOR A 3500# ACFT IS &320 FT/MIN. FOR WINDMILLING PROP AND GEAR DOWN CONFIGURATION THE RATE OF CLIMB IS -230 FT/MIN. EXAM OF THE ACFT AND LEFT ENGINE DID NOT REVEAL EVIDENCE OF ANY PREIMPACT FAILURE/MALFUNCTION.