When planning to upsize a raw image then neither use Camera Raw's sharpening feature nor Camera Raw's resize feature. Instead, convert it to an unsharpened RGB image at native size and load it into Photoshop.
There, upsize it to the required size using Image > Image Size, resampling method Bicubic Smoother. Then apply sharpening for source or capture sharpening. Then continue with other tweaks and edits. Finally apply sharpening for output, and print.
Using Camera Raw's built-in resizing and capture sharpening features are convenient to use but will lead to inferior results. In particular, the resize feature will add nasty (albeit tiny) ringing artifacts around high-contrast edges. They are not easy to detect but once you found them you'll start seeing them everywhere. They are so tiny you may decide to ignore them as they won't be visible on a print so what the heck? ... yet you should be aware of the issue.
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See the attached image above; click it to see it at full size (560 × 540 pixels, 51 KB). It's a crop which shows the rim of a back-lit sunflower's leaf against a dark background at 400 % view---so it's a tiny detail at huge magnification. The raw file has a native size of 3,008 × 2,000 pixels (6 MP). Part A has been upsized to 5,120 × 3,404 pixels (17.4 MP) and capture-sharpened in Camera Raw 4.5; it clearly shows the ringing artifacts mentioned above. Part B has been converted in Camera Raw 4.5 to 3,008 × 2,000 pixels unsharpened, then upsized to 5,120 × 3,404 pixels in Photoshop using Bicubic Smoother, then sharpened for source using Bruce Fraser's method, to match part A visually. Part B has very slightly better detail, and ringing artifacts are absent entirely.
-- Olaf