@pawsman Thanks for posting the pic in your systems page. Your photo and the subsequent discussions have helped clarify the confusion I previously had. As I thought, per what Eric has posted on his site, the 'upper half' of the DIs and the Impact Monitor are different. As is the porting. And efficiency.
@ky1mag Please note, that my comments are in reference to the Double Impact 'upper half' configuration and not of the Impact Monitors. I apologize, if I added to the confusion over this.
@ky1mag Please note, that my comments are in reference to the Double Impact 'upper half' configuration and not of the Impact Monitors. I apologize, if I added to the confusion over this.