Yes, the O.S. .18 CV-R is an awesome replacement. They can be bought for just over 100.00 and hold a tune. I've had several O.S. engines and they are very dependable. Couple it with a CVEC and it's insane.
Here's my MT Racer with some road rages on it. We were doing some high speed road passes to see how fast it would really go. It's the lightest and fastest single speed (still haven't installed the two speed) 1/10th scale car/truck I've owned. And this was before I got the throttle fixed. The stock setup never opened the throttle fully.
Spring is here and will be hopefully trying it this weekend. Just be prepared to pay for broken parts. I may have to look into brake upgrades.