Even if they are, one will be closer to the truth than the other probably. Look at the RPMs, go with whichever revs higher. HP is nothing, TORQUE at high revs is everything. It's no good having a high hp mill if it can only reach 26,000rpm, as you'll have no top speed. similarly, its no good having a 40,000 rpm screamer that stops pulling at 25,000. Is this for a buggy or a truggy? If it's for a buggy, go with one of the STS .21s, you'll be pleased (if not amazed) with the price and from what I've heard the performance too, even the STS .21 I bet would spank both of these motors you've mentioned, and then some. If it's a truggy, go with the STS .28 or .30, they are very good engines by all accounts, more for big wheeled vehicles, cos they have tremendous torque.

www.stsmicroengines.com