They came with locally sourced Borg Warner gearboxes, the pattern is different to the small blocks (top 3 bolts are the same, the lowers are off) I had the smallblock 904 bellhousing modified to bolt it up & the starter moved to the stock 265 position instead of down low for the smallblock.
There are only a handfull of blocks that will bolt directly to the sb torqueflite - these will have D36 or D37 stamped on the distributor pad. Some blocks have the extra material cast in at the rear but are not drilled for the torqueflite pattern.