King XP Performance Main Bearing Set (STDX) - NA/NB Miata (90-05)

King XP series main bearing set in King's STDX (StandardX) size (King MB5304XP STDX) for the 1.6L and 1.8L engines in the 1990-1997 Mazda Miata (NA) and 1999-2005 Miata (NB). King lists STDX as a separate size option next to Standard and does not publish a clearance figure for it. The set is five pairs of plain main shells.

• King XP series race bearing: a tri-metal, copper-based material with King's pMaxBlack overlay, which King credits with higher load capacity
• King lists the XP series for most race applications, including circle track, drag racing and off-shore, and other applications that use steel crankshafts
• Size: STDX, which King's catalog labels StandardX. King lists it separately from the Standard size and gives no clearance or wall-thickness figure for it
• Set contents: 5 pairs of plain main bearing shells (10 shells), one upper and one lower shell for each of the five main journals
• Dimensions King publishes for this family (standard size): main journal 49.94-49.96 mm, main housing bore 54.00-54.02 mm, shell length 17.5 mm, wall thickness 2.013 mm. King does not publish separate dimensions for each size
• King's size options for MB5304XP: Standard, STDX, 0.25mm, .026mm and 0.5mm. Measure the journals and oil clearance before choosing a size; King's catalog does not give a target clearance for this set

Fitment: Main bearings, all five journals. 1990-1997 Mazda Miata (NA, 1.6L and 1.8L) and 1999-2005 Mazda Miata (NB, 1.8L). King's catalog lists this bearing for the Mazda Miata 1.8L (1994-1997 and 1999-2005) and for the Mazda MX-5 1.6L (1989-1994) and 1.8L (1993-2005); the table shows those listings as US model years. King publishes the vehicle list for the MB5304XP family, and this part number is the STDX size option of that family. King does not list it for the 2006-on MX-5.

Part number: King MB5304XPSTDX

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