See either of these for sandwich plates, though it sounds like a local joint will be able to help you out:
http://www.racerpartswholesale.com/c...Sandwich_Plate
http://www.pegasusautoracing.com/gro...ID=OILFILTSAND

Pegasus has a nice looking billet plate at the bottom of their page, though I don't know anyone who's used it. I've used a generic Mocal one (without T-stat) in my old Honda for ~7 years with no issues with an FC RX7 cooler.

+1 on hydraulic lines, by the way. Wound up being cheaper than the SS-braided stuff, and wasn't abrasive to absolutely everything under the hood like the SS stuff would've been. You have to be able to give them lengths, hose diameter, and fitting angle though.

Edit: I don't know what the thread pitch and diameter is for the Miata filter. Anyone know which of those plates is the correct one?

resurrecting this thread to ask advice on what will happen to my bumper with the tight clearence. Dumb question since I'm betting it will melt/warp but should I just bite the bullet and go full crusher front? I've been holding off on that since I will have to (read: should) build self-supporting ducting from the mouth...

https://www.miataturbo.net/attachmen...ine=1405984312

Also, for anyone else thinking about doing this with a 1.6L...you need the spacer for the sandwich plate that FM sells or it won't fit.

Oil averages around peak 290* no? Should at worst make the paint unhappy, maybe slightly warp the bumper cover. Put some aluminum foil tape on the side that faces the heat exchanger as long as you cant see it, might help with some radiant heat.

Ok cool, good advice. Thanks

Absolute worst case, dremel out a little bit of the bumper where it's contacting.