any 1 heard of this gear oil? its called GFO (good fcuking oil) creeping up on my 60 k maint. and wanted to see if you guys had any input on this oil.. and also it only comes in 80w90(as far as i know) will that be a problem?i was planning on using it in the tranny and in the diff.. its $29 a gallon.. your guys input is appreciated