I don't understand your question ??
Most of the time, you will get a SOIC16 chip package on T400. On x200 as
well. But as you can't be sure of that, the only way to know it is to
disassemble and check by yourself.
The cool thing is that you can replace the SOIC16 chip with a SOIC8 one if
you want. There is pads below the chip to solder a smaller, SOIC8 one. I did
this on my T400, I replaced the old 8MiB SOIC16 chip with a 16MiB SOIC8 chip,
works perfectly.
Unfortunately, T400 involves a lot more of dissassembling to access the chip.
(In comparison to x200, where you only have to remove the palmrest &
keyboard. You can also quickly test if it flash succeeded by reconnecting
keyboard and applying power.
On T400, you will have to put the motherbard back in the chassis, apply
thermal paste again, reseat the heatsink, route the cables again, put the
keyboard.. and apply power fingers crossed ^^
