change GL account for valuation classes

This is vasanth . my client has different 5 plants . he wants to change gl account for valuation class.because the reason is (rawmaterial of steel&cement is being stored in spares and stores). The g/l account is 23010001 . This gl account has been assingned 13 valuation class . the valuation classes for steels&cement r 3040.3080 and 3090.

but the valuation area is defined at plant .there r 5 valuation areas . valuation class for all areas r 3040,3080 and 3090.

g/l account is also same.

is it advisable to change the g/l account.

give me solutions for this problem.