The 4mm hardware that is used on the cowl, wing retainer screws, and horizontal stab retainers is more than adaquate for the plane. I've been flying one of the Extras' for a year now with the 4mm hardware and no ill effects. Before that I had flown the Edge. If you wonder how hard I fly the plane, ask "RTK". He's been there, and I fly my Extra very hard indeed.

If you want to change anything, leave all the 4mm blind nuts where they are and change a few bolts out to allen heads. Just measure the bolt shaft from the bottom of the cap to the end of the threaded portion to get the correct length.

Pat