Need a replacement gas valve for the old Bryant 1/2 A643 gas valve (with pilot)

Google this part number [ GSV53CK198 ]. Look at it and see if it will work. It's a universal type gas valve that replaces a lot of obsolete ones. You'll find it at your nearest H.V.A.C. supply store. You won't find it in home depot. Replacing this gas valve is not something that you should be doing yourself so I suggest finding a trustworthy company. Let me know if this helps.