I use Amsoil Signature series full synthetic 5w30 on the Mustang GT and have a "preferred cutomer" account. And if you make over $100.00 purchase, they often times ship for free. Worth it to me. Check out www.amsoil.com
Random question. Does motor oil have a certain amount of wax in it like diesel fuel? I've always wondered if the white substance in the catch can is wax. Any thoughts?
Yes, I was gonna so suggest the same. Check your rear shock mounts to be sure they didn't crack etc... There is a reason why some companies make aftermarket shocks with stronger mounts. Seems to be a weak point once you stiffen everything up out back