Can I put a 600w hps in a closet thats 36" by 20" and 8 feet high?

I have a back area in my closet that measures 36" by 20" and 8 feet high and i have a cool hood with a 6 inch 265cfm inline fan and 3 computer fans. is heat going to be a problem with the 600w or should I bother with the 400w? from what I read its worth the trouble.
Any constructive criticism would be awesome..

I have 8 strong plants in veg with fox farm nutes. using a 2 foot by 4 lamp t-5 for now. just need help on the next step..
Thanks

Things going to get real crowded, real quick with 600 watts in that small space.... I have 9 plants in a 4 X4 foot grow tent with 1400 watts and thne over run the place....

is it remote ballasted where you can keep the ballast outside the grow area? so you want to use the 265 cfm fan to pull air through the air cooled hood and 3 computer for your exhaust fans? can you link me to some on the fan youve got or a similar one? im worried it may be a duct booster fan your talking about. duct booster fans are not as good as they look, they lose alot of their power just from the resistance of the air they suck through, they are made to be used as a booster for other fans blowing through ducting, on their own they are no good.

Its a fan tech centrifugal inline fan rated at 256 cfm, it well push some air but not a ton. i never used a cool hood before. i have plenty of room outside and above the closet in attic space to do just about any configuration. just don't know if its overkill?
the 600w i mean?

and yes. Its going to electronic ballast.

I have a 3.5 x 3.5 x 7tall with a 600W cooled hood. Its in my basement and ambiant temps down there are 65 or so. With no fans, temps will heat up in the 90's quick. I tried a pair of inline duct fans. It didnt do shit. Ended up with the 6" SolarPalau or whatever that brand is. Now it cools it right down to whatever temps I want. I suck allot of air out too. Your room is half this size, which means twice as hot. You'll need a real fan sucking air through the hood and probably air out of the room too.

Also, you're at over 100W per Sq Ft. Your creating allot of problems and wasting allot of light. A 400W will more than suffice. And dont push air, pull air....

i use a 400w hps and up to 400w of cfls depending on how large the plants are,in a area 36 in. wide, 20 in. deep, and 70 in tall. i wish i would of just went along with my gut feeling and went with 600w, but I was scared of heat as you are. Good news though-that fan will be acceptable. Now get another one for venting of the air inside the grow area while the other is hooked up to your airtight hood sucking cool air from outside the grow area and whisking away the bulbs heat right away. the ability to keep your ballast outside the grow area helps alot w/temps as well. so since you'll not have the ballast heating up the grow area and a cooled hood to whisk away the heat from the bulb- no, i dont think its overkill.