[ReCom]

Looking at showthread.php for vb 3.7.4, seems like there's no hook for putting stuff after first posts of showthread pages. Plus the codes that generate the simir threads listing are located way after (in term of execution flow) the codes that generate the postbits. The only choice is to totally modify your showthread.php by moving the codes that generate similar threads listing to before codes that generate the postbits. Easier said than done: you will have to be proficient in PHP and vBulletin architecture to understand the execution flow to make sure you don't mess up the file.