904 6 bolt crank flexplate internal balance

So while waiting for the stroker kit to come in I see that our new crank will be a 6 bolt our previous was a 8 bolt and we run a race convertor 8" with a 904,figures no problem but b&m only shows theirs for 727??? So in searching I see this cat product FP-440L states works with both and is the sfi i will need but the price just seems too good anybody run these in their 10 second heavy a body,should the bm 10230 work even though it states 727,I see these are all larger od than what we have,or i also see a hayes a prw brand as well.
I thought this would be a quick dial on the phone and part to the door,I don't want to have problems or go cheap here,so what are you all using out there