if you have all the paperwork that they signed receival, then there shouldnt be any worry...it's probably received by HPI already, just going thro the different departments....
you wont want to go back to the stock standard servo...
if you have the bucks, invest in a Hitec 7955TG titanium geared servo...(or any servo of similar torque)....
Or the cheaper EXI servos from Hobbypartz...
you've got a nice setup truck Shark...good on ya...
as for tuning, i think you're enjoying yourself....i'm pretty sure you LSN can be a tad leaner...and your HSN - definitely go lean more...as long as you see good trail of smoke, you shd be good...
And, I love the sound of your pipe!.. :P
sounds like a good idea Preacher....to be honest, i'm not sure what other engines out there will be better AND still use the same rotostart....The SH engine may use the rotostart...but they may not be better than the F4.6...
what version are you driving?....
since it's broken now, it might be worthwhile to get those HD gears and shaft, or even the delrin gear pieces from GPM...