HOT ROD SLED SHOP 850 ETEC head machining for improved performance. This head mod increases hp by slightly increasing compression and improving squish velocity. We have designed a way to both flat cut and radius the dome edge for a nice performance gain . This price is for the machine work only. Send your head to the shop and we need the squish numbers before you remove your head from the engine. Call with any questions. Price does not include return shipping.