Perhaps I'm wrong, having no personal experience with CAT or BT30 spindles, but my understanding is that these tooling systems are not compatible with a power draw bar of the Tormach design. No spring collet, so the up/down motion is no help. The Saunders R8 power drawbar design using an air tool to spin the drawbar might work.
You might want to review the Tormach 1100 design white paper. I thought there was something there about using the 3/4" R8 collet vs the BT style tool holding. What I recall is that the 1100 is small enough that the extra rigidity of the BT style isn't much value, and the gain from fast tool changes is worth the trade-off. I had the impression that Tormach offered the BT spindle early on as a compatibility feature (if you had BT tooling already).
Added: here's a discussion from another forum, but with several of our long-time (and expert) members weighing in. This is probably what I was recalling.
https://en.industryarena.com/forum/b...es--97445.html