I took out the 22 bolts from the belly pled the underfloor pipes with stainlate, used Plusgas as penetrant , and used a six sided one was very tight and rusty. painted plate both sides with POR15 ran a tap through the captive threads , copper grease on the return bolts I used stainless steel dome headed socket bolts ,because I had them in stock. replaced the under floor pipes with stainless, including brackets & bolts.