T-bird,
The ys 63 is much heavier than the FS 40S-C and doesn't have the rev capability. Also the FS 40S-C was meant to be a buggy replacement engine. And also, I didn't even think about it until yesterday... We'll have to see how the FS 40S-C does. Maybe the YS will end up in the buggy... who knows.

Later

BK