Getting The Right Compression Ratio...

The 60779 are a closed chamber design, 63ccs. They are meant for use with pistons that do not come out of the deck. Like the 340s from '73, or any 318/360. The 60179s are machined to have a large recess to mimick open chamber heads for the early 340s that had higher compression. but they cut is .060 deep, so you lose any possibility of quench. In other words, you give up a huge potential reason for using them in the first place. If you block was tall, like most factory blocks are, your pistons may NOT come out that .018". The only way to check is to measure the height of the piston when it's at the top of it's bore. Square decking allows the machinist to accurately machie the block to the hieght you specify. Standard decking or milling does not. The KBs are a flat top, but its called a shallow dome. Not a true total flat top design. It's modeled after the TRWs and Speed Pros that have been around for years. Great with open chambers, but not usable with closed 60779s. Keep asking questions. Newbiw isnt a lifetime monicker...lol