saving slices as tiffs?

I have a tiff image that is 4800x9600x200dpi. I have sliced it in ImageReady into 8 equal parts, but want to save the individual peices without loosing the resolution.

When I take the image back into Photoshop, and 'Save for Web',... it will keep the dimensions, but it the resolution to 72dpi.

How can I save these slices in the original format?

(I am currently getting around the issue by selecting the slice, and cutting the selection, and pasting in a new document. This is taking too long.)

Maybe there is a plugin I should be looking into for this?

No plugin, and no way to do it.

Slices are intended for web images only - which means JPEG, GIF or PNG.