I've noticed different times I was working on the bike that 1 of the exhaust header bolts spun freely, whereas the other got hung up.  It wasn't seized but it wasn't right either.  The other day I'm working on it and figure I need to get this bolt out once and for all.  Well, it broke flush with the head.

I drilled it out, and tried a bolt extractor to no avail.  I'm about to get froggy with the torch.    Any other suggestions?

I've seen this mentioned as a problem in the forums, but couldn't find a "solution."  Also, what bolts to replace these with?  I suspect the acorn cap screws would be hard to replace, or should I just order stock replacements from Suzuki?

Drill it close and pick the remnants out. Replace the goofy stock bolts with stainless steel, brass or bronze studs and nuts. Loctite the studs into the head. Anti-sieze on the nuts. Very 1930s Chrysler L6 manifold-esque... Works great and looks kinda cool.

I should follow this up with some details to save the next guy some time and aggravation.  

The bolts that hold the header on are M8x1.25.  Since the bolt extractor didn't work, even with heat, I stepped up drill bit sizes until 9/32", where I was able to remove the remaining bolt material.  (8mm = 5/16, but this would damage any existing threads, and I didn't want to do that).  I was able to tap the hole and it wasn't bad.

I got some stainless steel bolts (stainless all-thread isn't the easiest to find, but the local Sears Hardware has a good selection of stainless hardware), cut off the heads, and ran a dye down the threads to make sure they were clean.  Apply a little Lock-Tite to the base threads that screw into the head, tighten down, and install header using stainless nuts and washers.

Everything buttoned up nicely.  I slapped in a new donut gasket for good measure.  No leaks, no fuss, had a great ride testing it for issues.

One other note, while I had the exhaust apart, I figured it would be a good time to punch a 3/8" hole through the Dyna baffle.  It sounds so much better.