Even though the Blacktop head incorporates a more open up combustion chamber (see “Head combustion- chambers”) it still has an increased static compression ratio (see “compression ratio”), this is only due to piston style and design. The Silvertop piston contains a incredibly compact dome with two deeply angled exhaust flycuts, https://toyota4age79169.bcbloggers.com/30735023/details-fiction-and-toyota-4age-blacktop-engine-for-sale