rgrove (3/8/2010)
.....I *thought* that the bolt hole in the head for the stud is coarse thread, and you use that itched stud for the regular valve covers. If you had the t-bird dress up covers you had to get different studs that were coarse on one end (to go into the head) and fine pitch on the other for the dress-up nuts specific to those covers? Is my recollection wrong on that? cars still tucked in for the winter else id go check!Here are the dimensions for the rocker studs for the stock metal valve covers:5/16”-18 X 5/16”-24 X 3.86”
For the aluminum T-Bird covers the dimensions are:
5/16”-18 X 5/16”-24 X 4.125”
Coarse thread at the heads and fine threads for the valve cover nuts.

Lorena, Texas (South of Waco)