A .26 in a tiny stadium truck would be too powerful and too large. You would need many modifications for it to work, and probably many custom parts. For such a small truck, you need to think power to weight. Most of the trucks you see .26 engines in are 1/8 scale monster trucks that weigh around 15 lbs. I've heard of people fitting RC10GT's with .21 engines on other forums, and with available tranny hopups for the RC10GT and a sick mind, I'm sure you could fit a .21 in there. I'll see if I can find that post where I read about putting a .21 in a RC10GT.