The stock '93 Cobra t/b was 65mm.
I've
heard that the Chinese made Cobra intake available in the Ford catalog is a bit rougher casting than the originals and flow is down a bit.
If you get one of those you can always have it ported by TMoss:
http://www.tmossporting.com/tabid/310/Default.aspx
Both the reproduction and orignal Cobra intakes are on ebay pretty regular.
I got a real nice original upper and lower for $330 shipped. Which also included the t/b.
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