ORIGINAL: SNK SKNR

Ok, I think its time for some upgrades to my MT2....just wanted to make sure the parts I was lookin at were the right ones. First off, its basically a bone stock RTR MT2...so far here is the list...

[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGGP7&P=0]O.S. CV-RX .18 Engine[/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=000424471&I=LXJYM2&P=K]HPI Heavy-Duty Final Gear Set (2 of them)[/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=000424471&I=LXCLR3&P=K]HPI Engine Mount [/link]
[link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXDAP2&P=7]Motor Saver Air Filter[/link] (Is this the right size?)

Im sure there is more that will come as I break it. [>:] Couple questions: I can't seem to find the recommended washers on Tower Hobbies for the diffs (HPI Z891) am I missing something? Also, what kind of exhaust and header combo should I get? Should I just port the stock header and get a new tuned pipe? All those parts look right? Anything else anyone recommends to get me going?