Small block torque converter to flexplate

torque specs are based on bolt strength and what the mating part is, regardless of application. You could research the exact bolt size and application ( into a nut welded onto sheet metal ) and very likely find the same torque spec. Mechanical engineers were figuring all this out long before the first combustion engine was built. A better example of how mechanical engineers refer to prior knowledge is the pissy stamped tin speedy nuts mounting gauges to circuit board. Most people assume that cheap little nut was only cost cutting while in reality, the stud they go on is only sweged into a square hole in a thin/weak fiber board. The engineering torque spec for a actual steel 10-32 hex nut would likely crack that fiber board and ruin the gauge. so a weak nut applies to weak stud. OK... they could have required that board be made of heavier fiberglass or other material and applied heavier nuts and a higher torque spec. So maybe there was some cost cutting involved and the engineers worked with it.
And by the way... Torque specs in some books were found to be wrong. main example for this forum is torque spec for the bolts that hold down rocker shafts. They were printed at 30 Ft lbs in some books or manuals. A lot of ppl broke those bolts before finding the correct torque spec for that 5/16 bolt application is actually 18 lbs. I have a machinist handbook, some call machinist bible, and I have referred to it many times but then I have been into a lot more than cars in my time.
I have seen torque converter bolts that loosened over time ( more GM than Ford or Chrysler ) and lock tite is a degree of insurance for this application.