I, like my father before me, (whose stuff is now all over my garage...) am a pack rat, so I have some of every kind of hardware ever made....
I tried drywall screws myself when I did this. I ended up using a very thin, very aggressive, sheet metal screw.
As was mentioned, this isn't bridge construction here, you're working on carburetors.... Tappy tap vs. slam bang crash.
If all else fails, see Dinqua's site and pull the carbs off where you can see and get at everything.
Pat's carb site
