Repercussions of caching

I want to insert non-dynamic blocks but don't want the performance hit of cache being off. Can I just comment out the following lines in the module? Any Repercussions from this? Thankx much.

switch ($delta) {
case 0:
switch ($op) {
case 'description':
return t('Inserts the contents of a block into a node using [block:module=delta] tags.');
case 'prepare':
return $text;
case 'process':
return _insert_block_substitute_tags($text);
// case 'no cache':
// return TRUE;
}
break;
}
}