im running the os speed engine in my buggy and just picked up a rb c6bbt7 for my 8ight truggy. side by side i would say the speed revs higher and runs smoother throughout the entire rpm range. the c6 is wicked on the bottom and gets the large truggy moving quickly out of corners. for the money the c6 is the best motor ever. i got it for 449 with the 2045 pipe. its more engine than any buggy will ever need and suits truggys to a T. cant wait to find out which one lasts the longest. also the c6 only runs for like 7 min per tank. the speed i can get almost 10. not sure if its because the weight difference between buggy and truggy or not.