I am very happy with my 565cc 10mil Twister small block. It is just like the day I got it from Lew, unported. I have ran a best of 4.21 on it, i weigh 230. My jockey at 150 pounds has ran a best of 4.10. Quite sure it will run a bit faster as is, but it will be sent out very soon for some porting and gonna switch over to big flange pipes. Gregrob what reeds are you running CR125 or shee?? I switched over to CR 125 and it definetly made a difference, although my engine is a bit bigger than yours.