Wow...all this time I thought that the top part, above the shaft, of the distributor was the same between M37 and M715...I was under the impression that they if the shaft was swapped to the one needed for the vehicle in question...

Well...I dont know how much difference it will make...certainly different parts will make a difference but is it enough to affect performance or not??
Did Memphis say anything about the difference in the springs changing performance?.If they are selling them this way, hopefully, someone tried it and figured something out...