Thanks for the information. That will definitely help. I still find 147 3T datasets with TR of 1 second. A few other sites seem to have that TR also including Ann Arbor a and b and Berlin (Schmidt). This is the updated version of my script for checking the sites. I've attached the site list with TR of 1 and the corresponding subjects.

#!/bin/tcsh
# findTR1.csh
set tr1_dsets = 0

foreach rd (rest*.nii.gz)
nifti_tool -disp_hdr -infile_spec $rd |grep pixdim |grep "1.0 0.0 0.0" \
>& /dev/null
if ( ! $status ) then
echo "$rd has TR=1"
# strip off "rest_" and ".nii.gz" from name
set sub = `echo $rd | awk -F '.' '{print $1 }' | awk -F "_" '{print $2}'`
# check from which site this subject came
grep $sub *subjects.txt
@ tr1_dsets++
endif
end
echo ""
echo "Found $tr1_dsets with a TR of 1"