My terrova quit due to water intrusion. I found a great deal on 52" ultrex with ipilot link. Looking for advice on install from those of you who have done it. I am using thru bolt method, do I need 6 bolts or are 4 sufficient? I'm thinking 6 due to how heavy the ultrex is. My boat has the aluminum plate under the cap. I'm not sure if it is big enough to accommodate 6 bolts. Will be using stainless socket head cap bolts 1/4-20 with fender washers and nyloc nuts. Also, where is the best place to mount my heading sensor? Thanks for any tips/help anybody can offer.