R16 rocker bracket nut

[ppeters914]

What size is the nut to attach an SAE R16 rocker assembly? Is it special in any way? Grade? Heat treated? Size appears to be 7/16-20, but want to double-check before hitting Fastenal or ACE.

Is there a washer or washers?

I checked various manuals (paper and online). CarPartsManual.com shows the nut, no washers. Only found 2 images online, and both show no washers.

r16 rocker bracket nut.jpg

Thanks.

[JT68]

Pete. you don't need anything radical. Grade 8 is totally fine. Grade 5 would almost certainly do fine.

The priority here is not to over torque, 25-30 ft-lbs dry is plenty.

Use blue Loctite or a wavy washer if you are concerned about it. (other than vibration there is nothing trying to loosen it)

If you over torque, you may pull the studs from the head which is never a fun time.
(the 7/16 studs typically don't pull out, but the 10mm metric versions are a common failure point)

[ppeters914]

Thanks, JT.