RV-9A. The Crossbow AHRS in my 4500 recently "went West" and I plan on replacing the 4500 with a 5400. The 5400 needs an AHRS, and apparently there's a choice between an AHRS that mounts in place of the current Crossbow magnetometer, as opposed to the Dynon SV-AHRS-200 unit that requires a new/additional mount. I'm not clear on the relative possibilities, nor the merits of one vs the other. Can somebody 'splain that to me a little? I don't mind a little interior removal nor a little riveting...but what's the best way to manage the AHRS for a new 5400 replacing a 4500 with Crossbow?

BTW...on the subject of new AHRS and magnetometers....Van's calls for steel-shanked aluminum rivets and stainless-steel screws for mounting their OP-60 bracket. Is that OK, or do I need to be strictly non-ferrous?

Also BTW...in switching the 4500 to the 5400, do I need to make a new EFIS cable? -- change the current DB-9 to a DB-15?