And I went to Lowes last night with no luck finding what I needed as filler pieces. I looked for a 65mm > 50mm step down and found a cap, but the diameter of the insides is way too small to fit the gauge, and then I'd have to do the same for the speedo.
What size is your tach? I thought Defi's had all the replay shit on the sides? Is it removable or something?