Actually, there are many people who own the 5-port and have had 2-gallon plus run times on the piston & sleeve. The shortened time 5-ports seem to be only ones from the original production purchased from Asia directly. In my research, there is no reason to believe that a 5-port TZ that you purchase today will last any less run-time than a new 3-port. The contruction materials are identical.
Also, if you search hard enough on the web, most places are selling the non-ROAR legal 5-port for the exact same price as the 3-port motor.
Fuel mileage, horsepower and legalities are the only real true differences. If there is a ROAR 3-port rule where you race, get the 3-port. Most people have noted how well the 3-port performs, even against the 5-port TZ.
I don't think you can go wrong either way.
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