I disagree, the more info you give the converter people the better the converter with work for you. Dyno sheets are a good place to start, but real world numbers with a know converter can be very helpful. Shift points, cam specs, CID, launch rpm, gear ratio, and trans type all make a difference in building a converter to suit your application.
If you make more HP than you need and are slowing down to an Index, then the converter really isn't as critical, but if you are trying to utilize what you have to get to an Index, or for good repeatability bracket racing, you need a converter spec built to your car.
Hope This Helps, Dan