This is going to be confusing. The 998 can use the mega xducer? I'm using 2 xducers on my 998 the hd and a seperate 2d for high speed. Will I be able to use the 2d for the helix unit. If so will I need any other cables. Can I use the splitter I have and the switch I use to go between xducer on my 998. Thanks again