can 400 watt Sockets be Used for 1000 watt Sockets?

Basically i'm wondering if hid sockets are interchangeable i was thinking about buying a build it yourself ballast website below.. and i have spare 400 watt hid sockets. also does this seem like a good buy?? thanks.

http://www.growsmarthydroponics.com/HPS-1000w-Ready-to-Grow-Ballast-Kit-CLEARANCE_p_1395.html

The mogul sockets are classified as M59(400watt MH) or GU- something or MR or GX ect... And I can't figure out worth a damn for myself!
sorry, BUMP!

gonna say no. if they were for 600's originally i would say yes. the sockets normally arent heat rated for the extra watts. i have old 400 sockets i dont use anymore. they are noticeably smaller then my ones for my 600's. but the 600w reflector could be used for a 1000w . just dont think they would hold up..