They do have biscuit mount conversions. I've been picking brains all over the place, because I want to a Big Block Dart. Stuffing a BB in a Dart means fitment issues, it's tight. Many have said the 73-76 K-frame and steering is the way to go, and yes that means you also need conversion mounts.
This is one of those things that doesn't exactly make economic sense. I could do a SB and get pretty similar performance at a much lower price. And much easier too. But I want a Big Block Dart so I'm willing to jump through the hoops to get there.
