Joe, to mimic the inevitable conversionist who does not possess a drill press, BUT DOES possess a countersink, I am going to try just lightly countersinking the chassis side hold down holes.....I put the boards on the heat sinks and they look pretty close. Not close enough for an EXACT fit but with some of the wiggle room built into your stuff it might go. Worth a try and will add more info to your assembly instructions should some converter be in said condition with no access to a drill press....