If you slap one on right out of the box, I don't think you'll gain any power. The whole point of the MSD ready 2 run is everything inside of it is new and easily tunable. You can't easily tune the vacuum advance in a stock distributor. It can be done, but it's not the easiest to do. Plus the msd unit gets rid of all that 30 year old, worn out stuff under your hood and replaces all with new. Now a properly tuned msd will outperform a stock setup, but a well tuned stock setup will perform on par with a well tuned msd.