04-25-2009, 10:53 AM
It looks from the picture that you may be using the screw intended for the trucks on the coupler pocket instead. Most of the "classic" MDC kits I have picked up have two or even three different sizes of screws, and there's almost always an odd number too...! 
Anyway, since all screws of this type are small, and their lengths may differ only slightly, you might need to experiment a bit.
If that does not work, generally the metal underbodies can be drilled (slowly and carefully) with multipurpose bits. Since the screw has a chunky enough thread to be more or less self threading in the soft metal, you do not need to tap.
Good luck!
Andrew
Anyway, since all screws of this type are small, and their lengths may differ only slightly, you might need to experiment a bit.
If that does not work, generally the metal underbodies can be drilled (slowly and carefully) with multipurpose bits. Since the screw has a chunky enough thread to be more or less self threading in the soft metal, you do not need to tap.
Good luck!
Andrew