Replace a Rear Spool for a Rear Diff in the EMaxx? A good idea?

[rawfuls]

Sorry to make a new thread, but:

Would it be worth it to get a rear spool then messing with the diffs?
I know I keep changing my mind, but it just popped into my head.

Maybe something like this:
http://cgi.ebay.com/TRAXXAS-5381X-DI...lenotsupported

In this case, I can still use the 3.3 diff housing, and just replace the diffs, with the spool, but with the same cups/housing thing right?