3640 and WarpEngine in 3000

[T3000]

Read this first before cutting and hacking. Using the A3640 in an A3000

Then find a Warp Engine for the A3000.  This unit fits a bit better in the 3000 but you still might have to drill/cut the chassis for a fan.  
There's also a slightly different model for the A4000.

Hope this helps.