GT380 cylinder head nuts

[Craig380]

I rebuilt the top end of my '76 380 three years ago, with genuine Suzi head gaskets, new spring washers and nuts. Torqued down the head nuts to 26 lb-ft, retorqued after 50 and 500 miles.

I check the head nuts every 900 - 1000 miles, and every single time I've found that all of them are fine and tight ... APART from the two rear nuts, on the inlet side of the centre cylinder.

These two always need snugging back up to the right torque setting.

My question is this: is it worth winding on a second nut to sit on top of these two cylinder head nuts, to try and hold them securely? I'm guessing these two nuts are just slackening slightly in use.


Thanks for any input.