Jackson Auto Machine’s Cylinder heads are designed to suit your 4g63 performance demands. Every cylinder head is custom built to order which ensures it fulfills the customer’s power goals. We designed the first CNC Race Ported Cylinder head package for our 1st & 2nd Gen customers. With our extensive track experience we provide our customers with the best possible performance value. We use only Dyno tested, Race Track proven techniques in our builds. You will make more power with with our port design!