I have an '89 f-250 that needs a new head gasket. I was told that the IDI's have torque to yield head bolts. I was wondering if this is true and how to torque them properly. Thanks.
No, they are not TTY. But, the 6.9 head bolts are 7/16ths and can stretch. Therefore, the headbolts should not be reused on the 6.9 IDI. The 7.3 IDI uses 1/2 bolts and can be reused.