The ALDA Delete replaces the ALDA on top of you injection pump. The ALDA limits the amount of fuel available per the amount of boost you have built up. By deleting the ALDA, you gain full fuel on demand. This does absolutely nothing to peak power, but will really wake this engine up on the bottom end! A pyrometer is strongly encouraged when running without an ALDA. KEEP YOUR ALDA FOR FUTURE PUMP UPGRADES! When getting an upgraded pump, builders will require you to send your old pump in with the ALDA installed! Don't fall for the knock-offs on the market. The others I've seen actually limit your fuel because they are not machined correctly.