This should work for any version. I found an older version of this and did not see any updates, so here is something that will work for anyone.

Credits goto:
Original Maker of Disable Postcount
Author: Paul41598

Find this template
"includes/functions_databuild.php"

FIND THIS:

function delete_thread($threadid, $countposts = true, $physicaldel = true, $delinfo = NULL, $dolog = true, $threadinfo = NULL)
{
global $vbulletin, $vbphrase;


Under This line "global $vbulletin, $vbphrase;"

ADD THIS:
$countposts = false;

FIND THIS:

function delete_post($postid, $countposts = true, $threadid = 0, $physicaldel = true, $delinfo = NULL, $dolog = true)
{
global $vbulletin, $vbphrase, $threadinfo;

Under this line "global $vbulletin, $vbphrase, $threadinfo;"

ADD THIS:
$countposts = false;

save your file and go test!!! noone's post count should drop anymore.