The Briggs “16 common mistakes” says use no more than 3/4″ offset. I measured the offset my builder used, it is 1 3/4″. Because it was offset so far, only the 2 most left bolts holes would let a bolt through. Doubly screwed, offset 1″ too far and only 2 bolts of the 6 bolt holes used. No wonder it slipped. The inexpensive choice is to get a 3/4″ plate and drill it. I will go to Gorilla Metals or REM tomorrow.