hobao hyper 7 rally cross

[trinbagonet]

HI there,
I just got a hobao hyper 7 really cross
I was wondering if I can use this

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=330234340124

will work with my car..

 

[solly69]

invalid item

 

[trinbagonet]

OFNA Titanium Main Gear 46T
THY7046T

 

[trinbagonet]

HI there,
I still have lots of questions I am new to all this so forgive me but..

The car comes with a .21 engine would it be possibe to just put in a .28 engine or would I have to change other things on the car as well??
:\