savage spur gear

[ibanez830]

i was out at some sand hills in my town and while i was running it i heard a crazy rev sound and realised my truck wasn't moving, so i new it was the spur gear so i packed everything and went home. So the guy that i bought my truck off of had lots of spare parts and one of them was a 47 tooth heavey metal spur gear. now to my question, can i put that spur gear on my truck with a 15 tooth clutch bell? The stripped spur gear had 49 teeth and i dont want to put this 47 tooth spur gear on and mess something else up. on the package it says i need a racing clutch bell also but I'm going to my LHS to get one and another spur gear, but i need to no how many teeth i would need on a clutch bell to use this 47 tooth spur gear.
my plan is to get another stock spur gear and also get a new clutch bell that works with the heavey metal spur. so i can still use this heavey metal one as a spare. i just need to no how many teeth i would need on a clutch bell. sorry i no i wrote a lot but id really appreciate it if someone explained this to me
Thanks
heres the spare spur i have http://cgi.ebay.com/HPI-Savage-X-SS...ryZ44028QQssPageNameZWDVWQQrdZ1QQcmdZViewItem except its just the gear and pad thing

 

[Racer 1966]

The engine mount adjusts so you can use different clutch bell/spur combos. You need a hardened clutch bell for the steel spur.
Just be sure to set the mesh on the gears carefully. Just a very slight amount of looseness between the gears. Should be able to pinch a piece of paper with out tearing it but making a crisp fold.

 

[ibanez830]

Yeah i no all that stuff, so does it matter that the stock spur is 49 and the metal one is 47...will this affects anything, i no it will affect the speed but will a 15 tooth clutch bell work with that witout damaging it?
and I'm getting a new hardened clutch bell later this week
thanks