Hey I'm running to the store in about an hour.  Thought I had a full set of allen keys, but I don't have any that exactly fit the heads on the header bolts.  Can anyone tell me the size of these (i.e., allen key size to fit in the head)?

Thanks.

Its metric. Do you have a set of metric allen wrenches? If you do, get the one you're missing. If you don't have a metric set, buy a complete metric set since everything on the bike is metric.

it's 6 or 8mm, off the top of my head.

get the socket hex key set so you can throw it on your torque wrench. extensions necessary too.

Def, thanks.  I found a little hex key in a one off set that fits; will go match it up at home depot with sockets.

It is 6mm.I removed my exhaust earlier this week.