Shimano freewheel x 1/8"cog compatible?

i have bought a surly 18 1/8"cog and a shimano freewheel for my new fuji track and when they have arrived the cog is much fatter than the freewheel are they both going to be compatible?
from what i've been told 1/8" is the right size but i'm worried the freewheel wont fit properly

1/8" chain
1/8" or 3/32" chainring
1/8" or 3/32" cog or freewheel

It will work. As long as the chain's width is equal to or larger than either front or rear teeth, you have nothing to worry about.

I you want it all 'correct', go and swap the freewheel for a 1/8" one. But it will work as is. The cog is thicker, make sure the chain fits that, all will be well.

ok cheers i'm pretty sure the chain is 1/8"
i bought the freewheel from wiggle and it doesn't state what size it is on there and on velosolo it says it fits either 3/32 or 1/8 so i presume it must be ok
are there any good 1/8 freewheels out there then, or are they all much of a muchness?
saying that i only intend using it for a short time while i get used to the bike so i may as well stick with it

It'll be fine. If you were going to go singlespeed 4 lyf breddo ya get me, the White Industries one is rated, I do believe.

it bloody well ought to be for £65 :D

Buy cheaply, buy twice.