504 Gateway Time-out

First was problem with LIMIT.
1. I PUT THIS IN SECOND LINE WP-CONFIG.PHP
//increase WP Memory Limit
define(‘WP_MEMORY_LIMIT’, ‘128M’);
2.RESET: RESTORE DEFAULT IN HIGHEND OPTIONS/BACKUP SETTINGS
3. CLEAR ALL CACHED FILES WITH PLAGIN WP SUPER CACHE

HERE IS RESULTS:
Server Information: Apache/2
PHP Version: 5.3.13
WP Memory Limit: 128 MB
WP Max Upload Size: 20 MB
Max Execution Time: 120

BUT NOW IS PROBLEM:
504 Gateway Time-out

Which file to change:
1.WP Max Upload Size
2.504 Gateway Time-out
3.Max Execution Time from 120 to 400