Screws for attaching Yakima tracks...?

Does anyone think these screws will work. They are #8 3/4 truss washer heads. Ben from ATC said to use truss head #8 3/4, same threads as what you remove from the roof. It seems to me #10 would be better. They are more the right size for the track holes. These truss heads, #8, clear the towers for sliding. I'm not sure #10's would, or fit down in the channel. Any thoughts?...Thanks...

Anyone? Have Any Thoughts? Anyone that has put these on? Once they are on, they aren't coming off. I plan to smear the botton with 5200. Just want to use the right screws. I'm calling Chicali tomorrow. Thanks anyone...

I used # 10 x 3/4" stainless screws to attach mine.
The truss head screws will rust over time as they are just an electroplated steel.

Drill a small pilot hole so you have something for the tip to catch as the screw starts. Don't overtighten, the rib material is pretty thin. I used an rv vent sealant strip under the tracks and silicone in the holes before the screws were inserted and also over the heads after they were tightened.

Don't worry too much about the head clearance hitting the landing pads you can always shift the inch or so that you need to move the pad.
Dsrtrat

dezul... I just put my racks on a few months ago, but I haven't had them out in heavy use/rain yet. I used ss #8 truss head screws, 3/4" per Ben's comment. They seem to be fine and the best part is they lined up exactly where the factory screw holes were (the #8 hex heads with the rubber grommet), so no drilling.