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The hawks used F40s which had 38 and 40 mm pistons. These have 40 and 44 mm pistons. The F40 and F50 have the same dimensions but a few cosmetic differences.
I was going to use these and went with Cadillac JL9 calipers instead for future convenience.
Google it but I'm 98% certain the F50 caliper is the "cheap" brake upgrade 987 owners lean towards. (I had been thinking about picking one up since they are about $20-22k now.) If I'm right, suspect it'll be an easier sale with them.