I plan on getting an o.s.18 for my firestorm. Other than a different pilot shaft and exhaust header is there anything that I need to get to make it ready for the firestorm?

which one are you getting? the cvr or the tz? the cvr doesn't require a different header and is as close to a direct replacement that you will be able to find. you can use the same motor mounts but they will require some cutting to make them fit. I just did the CVR swap so if you need any more help if you go that route just let me know.

I was going to get the tz but what is the difference in the cvr and the tz?

TZ has alot more power, which will just cause your car to peel out more and is harder to control, but if speed is what you want then deff. get the TZ. Cvr is more manageable in my opinion, and has plenty of power for a firestorm.

the cvr is a side exhaust motor while the tz is a rear exhaust motor so if you go with that one you will need a new header. with the cvr you can use your stock header and save some money here are some specs on the two engine that I pulled off of tower O.S 18 TZ Practical RPM: 3,000-34,000 Output: 1.8ps @ 29,000 RPM. O.S 18 CVR Practical RPM: 3000-32,000 Power Output: 1.35 PS/28,000 RPM. if I remeber correctly I think That you stock motor has around 0.7 HP so the cvr is almost double but don't quote me on that.
Here ivs a vid of my firestorm with the cvr. the quality is real crappy but it will show you the kind of power you can expect. I am also running rich in the video as it is still somewhat in the breakin proccess.
http://s129.photobucket.com/albums/p...vidpics003.flv

Your link doesn't work.Erase the "¤t" and type "& current"(Without the space.).

Are the tranny's holding up to the tz's in the firestorm?

Probably.Its HPI...

Not enough people have tried them I take it

Sorry the link should work now

http://s129.photobucket.com/albums/p...vidpics003.flv

OK. Thanks for all the help.

Will this header work for the tz?[link]http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFAZ8&P=M[/link]

That header should work for the TZ but It won't fit on you forestorm. you'll need to find a 90 degree header so the exhaust will fit together.