Need engine choice insight, PLEASE HELP

[zr1600]

Well, im 6'3, and 270. I bought a classic cruiser frame kit, and i need to get a motor. I want to go with a briggs or tecumseh. What horsepower is good, and whats the best way to go for gear reduction? TAV or clutch? What gears and sprocket should i go wtih. I want to get atleast 50 mph outta it. 55 would be a dream. I found a new 11 h.p tecumseh on ebay, but dont know if it is a good one that will get me my speed.

[Woodchuckscustoms.com]

Hello my brother is about the same size as yall. we put a briggs animal motor with a norm racing clutch 12 tooth and a 52 tooth spocket and he has gotten up to 67 mph but that's was at 2/3rds throttle. If ya want speed spend the dust on a racing motor. The stock clones ,hondas and tec. are all good choices but you will only get about 40mph out of them:cheers: