you can get lead weights with self sticking tape on one side from auto parts stores. the contest is here, on top of the redcat forum, its a sticky, and only wheelie with the tsunami is off a jump, its a single speed and whelies easier now off the jump with the single speed but besides that, its all stock.
The Jato has tons of power in such a small package. The tsunami weighs way more. Another thing that hurts the tsunami is the rotary carb. rotary is not as responsive as a slide carb. If you could put the traxxas 3.3 in the tsunami I bet it would wheelie for a few seconds before it totally tears up teh drivetrain.
Dont get me wrong. The os cvr is a great engine. Plenty of power but not as quick as a slide carb os engine like the os 18tm or cvrx. If you look at your carb on teh stock vx engine thats a rotary carb.
I think you will be fine. ehroof runs a cvr on his redcats with no problems. I have not heard of any diff problems. I have seen drive shafts break. I installed a Peak Racing Diablo .15 on my sons tsunami and the first run out it snapped the rear drive shaft in half.
Wait you said the last thing you need is more power that will tear up the drivetrain now you want more power. If you dont want constant problems just keep the os stock. The tsunami cant handle more power than the cvrx. My Diablo is a .15 size engine but it has alot more power than the vx .18. I dont think it has more power than the os engine but it does have higher rpm's over the os. Normally the diablo goes for just under $200.