The bellhousing on the 235 is different than what's on any TH350, 700R4, 200R4, etc. The driveshaft for your cast iron pg is also longer, so you would need both an adapter and to shorten the driveshaft. It's not just a direct swap unfortunately.
I learned this when I swapped the 235for a 350 in my 62 Bel Air and also had to swap the cast iron power glide.
