|April 16, 2007 - In 2001, Mazda added a Main Bearing Support Plate to the Miata engine (top).|
It's basically a super windage tray that bolts on to four of the main caps. The 1994-00 version is below. It needs a bit of modification to clear the ARP studs - the larger outer holes in each little "valley" are ones I added for this purpose.
Right, there's that done - but I don't seem to have a 2001 oil pan! Whoops. So maybe I'll have to go with the earlier design after all this.