You'd have to be turning the SSC 7" prop over 30000 rpm to get near supersonic! I do agree the old Fox 15 does run pretty good. I just never liked the carb mounting method. I have a shoebox full of my old Mark IVs from my CL combat days. I miss that more than anything but the destruction and the speed they were going just got to be too much for me.
basmntdweller