It's from a 97 Challenger. Should be an 11/22 if it hasn't been repitched.
AND... it wouldn't have been a "Swirl" impeller. If it is... it's been reworked.
Can you post a couple pictures??
Regardless... no, it won't be a good impeller for a spring seat 800 XP. The pitch is too shallow. You will loose top speed, and you will probably be bouncing off the rev limiter at full throttle.