X220 Fan Replacement Question

[camdecoster]

I'm going to replace the CPU fan assembly on my X220 and I need to know which part to use. The replacement part for the X220 is 04W0435 according to the hardware manual, but I've read that people have made this replacement with the X230 part (04W6923). Does anyone know if these are the same part? Is the X230 part better than the X220 part? I know that either one will work, but I'd like to get the better one. Thank you for your help.