This was recently covered on this board. The bolts will be torqued to a specific torque. Then they are turned another 90 degrees to set the final torque position. The bolts have a minimum thickness and should be measured to be sure they are in spec. When the last 90 degrees is achieved they may actually be at a lower torque setting as the bolts stretch so they cannot be tightened by torque alone. I am only an amateur and my response is paraphrased. Perhaps you can find the right thread.
'85 SL500 Euro