[Healeys] Request for stock 6-cylinder valve cover nut dimensions

[Patton.Dickson at gmail.com]

Hi everyone, first post in a VERY long time

I am taking a metal lathe class this weekend, and the instructor asked us to bring a sketched out project to class. I plan to machine a set of period-style extended barrel hold-down nuts with knurled tops for an aftermarket aluminum valve cover I bought years ago for my BN4. 

To ensure my internal bore depth and shoulder geometry account properly for the factory rocker pedestal studs, I want to cross-reference my setup against the original factory spec. If anyone has a loose stock valve cover nut handy, could you verify a few quick measurements with a caliper? The valve cover nuts I have are the stock ones currently on my car.

 - Overall Length: Total length including the sleeve/barrel.
 - Sleeve Outer Diameter: Diameter of the lower barrel that extends down into the cover well.
 - Thread Depth: Effective internal thread length before the blind end.

I am pretty sure the thread spec is 5/16"-24 UNF”can anyone verify that as well?

Appreciate the help getting these numbers checked before I start the class this weekend.

Patton 

Patton Dickson
Plano, TX
57 “Longbridge” BN-4