Good point.

You can do this entirely in T-SQL by concatenating the [text] field into a seperate table that has a field with a text datatype (thus allowing more than 8000 characters).  You can then safely perform a like comparison.

It's a bit awkward though and given how remote the chances of this occurring are, unless it's an essential part of an app you're building, you might as well just script the procs and do a Find/Replace search.  Or accept the risk.