They all have the small converter bolts but that shouldn’t be a problem for you. None of the production B/RB had big bolts except Hemi and MaxWedge.

If you have a loose input shaft stick it in the converter and spin it a few times then pull the drain plug. If no metallic debris comes out its probably a good unit.

You won’t know stall speed until you get it in the car.

If you can take a good clear shot in each converter the stator may have some ID on it that can help you determine stall speed.

Post some pics and I’ll see if it will help.