I'm thinking about up grading my 1978 sc with 964 cams and je pistons which would raise my compression to 9.8.1! Do you think this would make a large difference in the performance of this car. It already has the back dated exchangers and no cat!!!

 

You will be very pleased with this set up. It offers great low end response with a lot more umph in the midrange and upper end. If you really want to sqeeze her tein plug her and raise the CR even more. You can run a Electromotive HPX or HPV1 iginton and watch that baby roll! Either way the upgrade you are making is a good one and will please you.
Stephen

 

Do those Electromotive systems use a knock-sensor?

 

Yes, some do...There are several units. Unless you are going to run a different valve train the noise really will prohibit the use of a knock sensor. To much noise.
Stephen