We change a lot of front main seals and oil pump cover o-rings here at OTRAMM. Holding the crank pulley while torquing the bolt to 300+ foot pounds has always been an issue. Over the last few years I've gone through several iterations of the tool we use at the shop. I've finally got it just how I like it. I figured other 80 Series owners would likely be interested as well so here they are! They're 1/2" steel laser cut and then the 1/2" and 3/4"square drives are broached in for a precision fit on your breaker bar.