The Daihatsu engine used in the Cushman was a 47 hp at 7500rpm. It was restricted in two ways. The governor controlled the speed. It was a Cushman exclusive called a ground speed governor. It was accurate + or - 25 rpm. It kept the speed accurate for spraying, top dressing, etc. The truckster used models also had a small resticter bracket on the trottle arm that kept the carburator from opening no more than one third. This was because the rest of the drive train was only good for about thirty HP. I was in the first service school in Lincoln NE when it was introduced. I just purchased a 93 turf truckster with that engine Saturday. It is different in important ways from the On road truck and the off road truck imported in the same era. Breater, carb, intake differences make it very difficult if not practical to swap parts. The 327 was 3 cylinder 27 hp at 3600 rpm.