I might add that if it's done on a CNC machine, it gets the decks perfectly parallel to the crank centerline. I've seen some that needed as much as .020 more off of one corner than others due to less stringent quality control at the factory. If you have .075 quench and low compression, it doesn't do much good. However, if you're building a performance engine, this gets everything much, much closer to uniform which can be worth some ponies. I deck all of mine that I use for any kind of performance. My machinist says that there's no real advantage to going to absolute zero and they do most with the slug .005 in the hole. You can run a .030 or .035 gasket, whatever you're comfortable with, and it leaves just a smidge for a future cleanup if needed.
A forum community dedicated to 1st generation Chevy Camaros owners and enthusiasts. Come join the discussion about performance, builds, restoration, modifications, classifieds, troubleshooting, reviews, and more!