Yes, it is possible to use 365 nm or 334 nm.
The calculations used in the kit booklets and the MegaCalc applications are set for readings at 340 nm [extinction coefficient for NADH of 6.3 (1 x mol-1 x cm-1)].
For absorbance readings at 365 nm (Hg lamp; ext. coeff. 3.4) multiply the calculated values by 1.8529.
For absorbance readings at 334 nm (Hg lamp; ext. coeff. 6.18) multiply the calculated values by 1.0194.