I agree with the richer bottom end. I run 48 pilots and on the dyno they are a little rich but not so much that I feel the need to change them. I run 155 mains and stock needles with no shims. I tried the TBS needles and didn't like them so I switched back. 45 pilots would probably have put me pretty close to a perfect A/F mixture. With the 48 pilots once my needles (mains) come into play my A/F mix is just about perfect for where I live.(Elevation/humidity) I could probably go 45 pilots and 1 shim but I am happy where it is now.

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