Nice find.

I spent a little time with stock 40s and early 50s Dodge FH 6s. One was in a 49 with the hydra drive (can't think of the actual name they had for it... Fluid Drive I think), the other a 52 1/2 ton PU. And if I remember right ther were a little larger in CI... longer stroked maybe, but maybe not, than your 33.

I have never heard of any after market... but really have never looked. BUT I do know this. The old FH chrysler 6s were long stroked and while they could pull 100% at 1800 rpm for 40 years they did not handle high revs (by high I mean over like 3200). Bottom ends simply flew apart (lube issues maybe???). Dad's 52 basically topped out at 50 mph or so... but it could pull a semi at 20 (and did once!.. was hard on the clutch though)

I'll be watching this as I'm curious too. I wonder what MOPAR has (Direct Connection... but they may have changed their name by now). Been a while.