i just picked up a civic a few weeks ago n notice the seat moved. with closer inspection i notice that one of the holes where stripped so the bolt would not go in..its the rear right size bolt..does anyone no what the thread size is so i can retap it? or mayb go on size bigger

 

It is either 8 x 1.25 or 10 x 1.25. Remove the other three bolts and compare.
Use drawings at www.bkhondaparts.com to double check nominal diameter and length.
Drawings showing this are in the shop manuals linked at http://ww1.honda.co.uk/car/owner/workshop.html