tcrews said:The MSD DIS-4 does all the Boost-a-Spark does and a whole lot more
Spark boost, adjustable timing pull (from X-rpm to spark-kill rpm), RPM set spark kill, two-step rev-limit (for setting the launch rpm you want to leave the light at), and theft (complete spark kill, wire a hidden switch to completely kill your spark).
If all you need/want is to boost your spark the KB unit should be fine. If you'd like to be able to pull a few extra degrees of timing depending on weather, etc.. and or set a spark kill rev-limit instead of the factory fuel kill and/or would use the two-step feature the MSD would be a better choice.
I have an MSD unit......it recently died, why I really don't know. I've heard MSD is very responsive when it comes to replacing them though.
Yes, you have the ability to pull timing from X-rpm to the rpm you set as your cut-off. I used mine to pull an extra 3 degrees from 6,500rpm to 7,000rpm. It's progressive so it starts pulling at 6,500 and by 7,000 it would have pulled a total of 3 degrees.Bright Blue Cobra said:correct me if I'm wrong, but I don't think you can adjust timing between certain ranges with the MSD on 96-98 cobras, just set the spark kill and two-step rev-limit.