yes, 12 tou of warp would qualify for a resurfacing.

BUT, I would suggest that you remove the camshaft and remeasure....hopefully using a "good" straightedge, Why? to remove any effects having the camshaft in place when you are checking the deck flat.

Personally, I would pull the cam, remeasure the deck for warpage, and see if the 'warp' is a 'perfect' warp or if it is a twisted warp.

By 'perfect', I mean that the deck is true side to side, but has a warp from end to end. By 'twisted'. I mean that the deck is twisted from end to end, with warpage more down one side than the other.

Why bring this up? because I have installed a 'perfectly warped' 398 SCP head on my B21FT [it was warped 5 thou] using a Cometic MLS HG, [and did so with the camshaft NOT installed].

I had zero problems with sealing compression or coolant: and had no prblems running 10+ psi of boost for well over 50K miles.

I would probably do the same thing with a 12 thou perfectly warped head, BUT ONLY if using a Cometic MLS HG. Trying it using an OE style composite HG would not work.

I realize that the usual approach is to just go have the head resurfaced, But, I don't care to lose any more alloy from a head deck than absolutely necessary.

good luck, though

TF