Originally Posted by Chris Peralta

Funny that you say the D8T was fast with the on-road motor. The C6USA actually uses an on-road crankshaft with the standard C6 piston and sleeve and it is a beast in a truggy. The on-road motors are designed for all out power for a car with a TON of traction so it can be a pretty violent power band in an off-road car.

The K9/10 engines have a pretty aggressive timing on the crankshaft somewhat similar to what an on-road engine would use, the B10 is not as aggressive but like you said it also gets better fuel mileage. If you really do like the K9 a lot I would say get yourself a new K10 and stick with what you like.