FileContent=$(awk '{print $0}' largeFile2) # this is where I think I have a problem :

# LINE contains start and offset identifying each record in largeFile2

while read LINE;do 
pass=1
for results in $LINE; do
if [[ $pass -eq 1 ]];then 
from=$results
pass=2
else to=$results
fi
done
(( from=$val1+1 ))
(( to=$val1+$val2 ))
newOut=$(echo $FileContent|cut -c $from-$to)
echo $newOut >> newfile
done < indexFile1