Tekkit 3.1.2 download?

[9302u76]

Hello everyone! I really want to play Tekkit with my friend, and be able to use engines. I can't use engines ingame (single or mutliplayer) because when I power them either the server or the game crashes. I asked a guy and he said that it was because tekkit's buildcraft was a bit buggy in 3.1.3 and he said he recommended me to downgrade to 3.1.2, so I tried to do that. I downloaded the 3.1.2 server but I can't find the 3.1.2 client, so I can't log on to my server. Is there anywhere I can download Tekkit 3.1.2 (the client, not the server) and therefore get able to play with my friends and being able to mess around with engines?

Fast and helpfull answers really appreciated! Thanks!