Went over to help Mark(bada44) get his ATS 545rfe trans in his truck. While I was there, he showed me the 8HP70 trans. It's a little smaller and lighter than the 545rfe trans. Thought the 8HP70 trans was bigger and weighed more... That's a nice surprise.
it's 30-ish pounds lighter. and there are no clearance issues anywhere, which is very nice.