Why don't you just replace the 'grep' command in the 'find' with 'sed' ? Like so:
Code:
find . -type f -exec sed -i 's/text/replacement/g' \{\} \;
You might want to do a test-run without the '-i' to see what it will do (without '-i' or '--in-place' 'sed' will just output the result of it's editing to standard out), probably piping the output to 'less'.
Holger