Curious; why do you want to?
Assuming that we are talking about the Huawei stock ROMs, as the U8650 runs 2.3.3 (Gingerbread) and the U8800 runs 2.2.1 (Froyo), you would be going backwards.
Unless you mean customised ROM on the U8650. AFAIK no one is working on a port to the U8650, although I may be wrong.
Given that they use different CPU's (with differing ARM instruction sets ARM6 vs ARM7), different GPU's, different screens and different phone controllers, I think that the likelihood of success without a specific port is low.