10" clutch disc

I used a 10" HD slant six clutch kit behind my 225.
I bought it from Rockauto for just over $100.
It does require special pressure plate mounting bolts that I got from Brewers. $36 for 6.
You didn't specify if you have a 273 or /6 though.
Or Brewer Performance has a kit. You will need the correct pressure plate to go along with that 10" disc.