Chris King makes threaded 1" headsets with stack heights as low as 33.0 mm. Campy's web site says the Record threaded headset has a stackheight of 36.5 mm so the CK gets you the extra space you need.
Going downscale a bit, Tange's Vantage DL 1" threaded headset has a stackheight of only 32.8 mm.