I'm running something like this:
create table #tmp (line varchar(max))
insert into #tmp
exec sp_helptext 'sp_Blitz'
declare @version varchar(50);
select @version=Left@version = Left(line, CHARINDEX('''',line,CHARINDEX('''',line,1)+1))
from #tmp
where line like '%@Version =%'
set @version = reverse(left(REVERSE(@version),CHARINDEX('''',reverse(@version),2)))
select replace(@version,'''','')
drop table #tmp