Head bolt tightening performance

Hi everyone
I've seen some talk about a three-stage cylinder head tightening sequence for the stretchy head bolts that I think my 1991 Clipper 1.8 (not GTI) has got - I'm just off to buy some new head bolts since I realise I need to replace them according to what people are saying! But I don't know what the torgue settings are - could anyone quote from the Haynes manual the torque settings  that i need to tighten them to ?

Thanks !

Rob

tighten to 40 Nm
then to 60 Nm
then 1/2 turn 180%

 
The last 180% feels like the bolts are going to snap ! Buy or make a dial guage

Thanks Chudd! Hopefully the bolts won't snap!