TEC help needed.

[Fitseries3]

im not a total noob here but i figured that i would be better to ask before i kill anything.

i have a swiftech MCW6500-T (http://www.petrastechshop.com/swmcthwa1ins.html) and i have been using it for a year now just fine.

it is cooled by 2xpa120.3's which may be overkill but i figured it was best to overshoot than fry a chip/tec. im using a iwaki rd30 as a pump so i have plenty of flow.

the stock pelt in my block is 226watts and keeps dualcores around 8c and quads around 15-19c

i recently bought a 400watt tec and wish to swap them out. the 400watt is the same size as the 226watt tec.

Questions:

1. how do i know which side is the HOT/COLD side of the new TEC?

2. would it be ok to underpower the TEC with a 450watt/20amp psu?

3. will i notice any difference?

4. can i power up the TEC without being in the block?

5. will a 500watt pc power and cooling psu (dedicated)(http://www.newegg.com/Product/Produc...82E16817703015) power this 400watt tec?

6. anything else i should know here?

thanks in advance.