The data set you are requesting is not available in the IRI Data Library. However, it may be available from the World Data Center for Paleoclimatology at the National Geophysical Data Center.
The CLIMAP data set is listed here:
http://www.ngdc.noaa.gov/paleo/datalist.html#paleoceanography
Within the "climap18" directory is a file named "rad_hays.txt", which might be related to your search. Please read the "readme" files within that directory or information which might be elsewhere on that website.
-- Michael Bell