These are the same heads as we use in our Big Block builds like this one.

You therefore know that we like them and they work. Another big advantage is that we almost always have them in stock.

We buy these Dart Pro 1 BBC cylinder heads as porter castings so that we can do the machining on our own CNCs.  The finished heads are therefore not the same as the Dart's.  The Dart machined heads are great, but ours flow even better and in our experience, make more horsepower.

How do we get these results? Because we are not doing high volume production like Dart, we are constantly tweeking the port designs on the heads we run through our Rottler 5-axis CNC.  The net result is that the geometry of our finished cylinder heads is constantly evolving whereas an OE's design will be more static.  Another big advantage we have is our our Newen CNC seat & guide machine.  Check out the videos below to see these machines at work and the advantages the Newen brings to cylinder head machining.  Why don't all shops have a Newen? Simple - they cost a ton of money.

The assembled heads are available assembled for either hydraulic or mechanical cam applications. The mechanical cam standard version uses Dart Severe Duty stainless steel intake valves and Dart Inconel exhaust valves. Manley Severe Duty valves are standard for the hydraulic cam version. We use Manley spring kits with 10 degree hardened steel locks and titanium retainers for both versions.  Spring set specifications the hydraulic roller and mechanical cam versions are as shown below:

Hydraulic: Professional, Dual Spring, 507 lb/in Spring Rate, 1.190 inch Coil Bind, 1.550 inch OD

Mechanical:  NexTek, Dual Spring, 604 lb/in Spring Rate, 1.150 inch Coil Bind, 1.640 inch OD

Please call us with any questions at 815-725-2727.

ROCKER ARMS IN PHOTOS ARE NOT INCLUDED

Payments Type Accepted:  Cash, credit card, wire transfer