Looking to lower my 400ex

I think the 300ex shocks are lower, but I'm not sure the exact spec. Does anyone know what the eye to eye length is for these 3 models?

Is the bushing size the same (width of shock mount) so all shocks are interchangeable, minus the shock length.

Please fill in the blanks...

400ex eye to eye~?
300ex eye to eye~?
250ex eye to eye~?

This is for the FRONT shocks only please.

Thanks!