viper center shock position

[ekimsx600]

I just bought viper shocks for my skid and was wondering which way the center shock is installed, threads up (on the w arm) or threads down (towards the rails). I can't remeber which way they go on the viper or if it even makes a difference. I know they go in threads up on a srx and down on a vmax. Any help would be cool.
Thanks

 

[Canuck]

Just checked my Viper, the threaded portion of the shock body is up.