Dart Mercury 525, 600, 700 EFI Aluminum PRO 1 Cylinder Heads - with Valves Only (Pair)
Dart machinery has just introduced the ultimate Mercury Racing replacement aluminum cylinder heads for the Mercury Racing 525, 600, and 700EFI engines. These are available in three upgraded intake runner sizes 310CC, 325CC or 345cc ports. All heads have a Dart Marine exclusive chromate finish that provides a superior corrosion resistance extending the life of the heads in a harshest of marine environments. These heads are sold as heads w/valves only or completely assemble with inconnel exhaust valves & dual valve springs.
PRO1 aluminum big-block cylinder heads deliver "out-of-the-box" airflow that beatsthe competition - at an unbeatable price! Specifically designed forperformance marine engines, PRO 1 heads make Pro Stock airflow technologyaffordable for every big-block owner.
Inspired by our championship-winning Pro Stockdesigns, the PRO 1 's race-proven features include rolled valve angles, improvedspark plug location, extra-long intake valves, raised exhaust ports, andfast-burn chambers - yet the PRO 1 can be used with off-the-shelf pistons, valvetrain components, and intake manifolds. You get more power for your moneywith PRO 1.
Using advanced manufacturing techniques, we cast the PRO 1's ports with incredible accuracy. This precision casting technologyduplicates the contours that were previously available only in hand-portedcylinder heads.
- Premium alloy: Dart aluminum heads are cast from virgin 356-T6 aerospace aluminum alloy for superior strength and integrity.
- Bolt on compatibility: 2° rolled valve angle and standard spacing. Accommodates all stock accessories
- Heart-shaped 119cc chambers improve combustion efficiency.
- Raised spark plug location improves flame travel for a quicker, more complete burn - producing more power.
- Multi-angle intake seats and radiused exhaust seats dramatically increase airflow.
- Hardened exhaust seats are compatible with unleaded gasoline.
- Exhaust ports raised .300" to improve flow (requires 1" longer head bolts next to exhaust ports).
- Spark plug holes are machined and gasketed for 3/4" reach plugs.
- Manganese bronze valve guides extend cylinder head life and reduce stem wear.
- As-cast heads are bowl blended on 5-axis CNC machining centers.
- Head Assemblies include heavy-duty marine stainless steel intake valves and inconel exhaust valves.
- NEW Dielectric hardcoat surface treatment protects aluminum cylinder heads against corrosion from saltwater environments.
Final Assemblies Require Parts Kit which includes: Valve springs,retainers, locks, seals, studs & guideplates. (Sold Separately)