i have a GS storm, and the conversion to make it a truggy is kind of expensive, and i don't even really race i either drive on the street or in dirt/mud, so i dont' really need it even though it looks hella cool, i'll probably just take that money and buy a mammoth.. i just put some dominator tires on the storm, and even though it looks retarded, what kind of set up (diff oil, shock oil, shock springs) should i run if i'm bashing?

You oils set up wll work ok the way they are, maybe some stiff springs would help a little for bashing

Your real problem will be gearing
Just throwing on Monster wheels with out gearing down is going to make it run hot and really strain your clutch set up

I did the same on my H7 rtr about a year ago, it had crazy fast top end speed but no torque and burned up clutch shoes like crazy.

well is the 13t bell like the one from the SUT good? i don't have the .25 either it's a .21

Keep in mind
If you are using the stock 46 tooth spur with a 13 tooth bell gear ratio is 3.5-1
Id go with an Ofna 12 tooth bell, that would help some at 3.8-1
The conversion gives you a 54 tooth spur with the stock 13 tooth bell it is 4.1-1
If you really want a hole shot machine 54-12 gives you 4.5-1, that would be great on a small technical track.

At least with the 12 tooth bell it would help lower the gearing some
All you really need since you're running the Dom wheels is the Spur and Diff raising parts

But I think a $169 for the conversion kit is reasonable for all you get
The Pro chassis, Body(not the sexiest), Spur gear, tire/wheel(crappy ones I know thats what ebay is for), Wheel adaptors, shock towers, body mounts,etc, etc.

yea, i think i'll just get the kit, but i dont' have the money right now, what are good street tires for a buggy?

For just messing around, Road Rages by proline work well and last a long time

Ofna has a few tread designs to choose from too