what thread size are the bolts that hold the cover on a 10bolt?

i have a TA girdle.. i plan to just buy 10 studs and 10 nuts/washers to hold it on... but i need to know what thread size the bolts are.

id like to pick the bolts up on my way home from work tonight, so i cant just go under there, pull the top bolt, drive to the store and compare...

anyone know?

 

5/16"-18 x 1"

What you're talking about won't really work, unless you're going to put the nuts and washers on top of the cover; they won't go down into the counterbore. Yuck. Besides mostly defeating the girdle function.

A better thing to do would be to stop at Home Depot or the like, and pick up 10 Allen head bolts as described above. Then they'd at least sit down inside the holes, and somewhat brace the thing a little bit. 2 of the bolts are supposed to have a spacer washer that positively locates the cover on the flange.