Finally got it working, I had to tweak a few settings to get the additional information to show up first in front of Description...
here is what i had to put
add_filter( 'woocommerce_product_tabs', 'sb_woo_move_description_tab', 98);
function sb_woo_move_description_tab($tabs) {
$tabs['description']['priority'] = 10;
$tabs['additional_information']['priority'] = 5;
$tabs['reviews']['priority'] = 20;
return $tabs;
}
Thanks for your Help
works like a charm