I'm not running twins, built a fresh motor and two weeks later popped a hg. So we ended up just re torquing about 4 times the first week after we replaced it. And never really running over half throttle. Didnt want to put too much stress on it. Then twice a week for the next two weeks. Seems like a lot of work, but, knock on wood, no problems since. I also have 425s. And a stock thickness HG. They seem to be holding up fine to 50psi. for now. Just my 2 cents. Good luck man!