Since we only need more ram (and optionally more OneNand flash), why instead to try to use an OMAP 3630, not more simple try to replace PoP slice and still use an OMAP 3430 ?

I have seen some companies that sell TI PoP compatible chip with ram up to 2GB (and SLC Nand up to 4GB).
Furthermore there are even some motorola's and palm's old phones which still use Omap 3430 but with 512MB ram.

Of course it is always an hard (or for someone impossible) task, but there aren't the problems related to soc family change