Possible to get more hp from a 16hp Tecumsah?

Have a ST-16 with the Tecumsah 16hp OHV motor in it. Are there any little tricks to getting a little more hp from it? Like maybe a different camshaft or bigger jets in the carb? I love to tinker with these things and just found this site. I like it and alot of good info. I plan on doing some pulling with mine and just started by installing a new head gasket. Mine was shot.

Briggs & Stratton used to have a great site that told how to get more power from their 5 hp go-kart engines. The biggest single gain came from increasing the rpm and removing the muffler, similar efforts should work with your Tecumseh. Horsepower is a function of effort (torque) and time (rpm), so if you can turn the engine 50% faster and make the same torque you will be making 50% more horsepower. On a lawn tractor that is just used for mowing etc, that is not such a good trade off. The extra noise and wear vs. little, if any encreases in mowing efficiency. Now if you were building a pulling tractor.......that's different.

For my own efforts to increase power, I swapped out my Tecumseh 12 for an 18 hp, OHV Tecumseh with the auxilliary balance weights and everything fit. There was even an extra set of holes in the frame that when used lined the pulleys up properly. The clutch bracket even bolted up. The only problem was a high hour transmission that was not amused by the 50% increase in torque. A rebuilt transaxle from a ST16 helped.