Our 427ci mechanical-roller, iron LS long blocks come in two primary flavors: conventional or copper head gaskets. This build uses Cometic MLX gaskets which have a max boost rating of 35 psi. Copper head gaskets with fuel hoops will hold far more pressure, but may require occasional torque adjustments. Those long blocks have a different part selection to better work with the higher boost levels. The top of our LS horsepower ladder is the 462ci billet aluminum long block.
This long block is intended for Drag & Drive running gasoline on the street and either gasoline or alcohol on the track. The mechanical cam enables higher rpms and higher valve lift for more air flow. That means more horsepower. The mechanical roller lifters are less prone to failure than their hydraulic roller counterparts. One trade-off is that valve lash needs to be checked regularly. The adjustments are far less frequent than in years past thanks to improvements in valve train materials and design.
We use Dart SHP blocks and incorporate three major upgrades as part of our precision CNC block machining process. The first is going from 7/16 to 1/2 inch head studs. This greatly increases clamping force on the heads. Second is replacing the main bolts with main studs. The third is machining the lifter bores to 0.904" from the stock dimension of 0.842". The larger lifters are far more reliable at higher horsepower levels.
The rotating assembly starts with a 4.000" stroke, Callies Apex center counterweighted crankshaft paired with Ultra Enforcer I-beam connecting rods. Riding on the rods are 4.125" Diamond Race Series LS dish pistons. This combination yields a 427 cubic inch displacement. The ATI Super Damper is included in the price.
On top are our BRE-machined All Pro cylinder heads filled with the parts you need to push this engine to the limit. We start with raw castings so the ports, runners and combustion chamber are all custom. While we prefer LS7 ports, we can machine LS3 ports into the heads if that's what you need for your existing intake manifold. The port work does not change the valve angle which will remain at 12 degrees on the LS3 variant. The All Pro's are assembled with Inconel exhaust valves and Severe Duty Manley intake valves. The Manley NexTex spring kit has a coil bind rating of 0.960" allowing high valve lift.
The Jesel 1.7:1 shaft rockers stabilize the valve train at high rpms and allow easy valve lash adjustments. The mechanical roller lifters feature needleless bronze roller bearings.
Some of the other key features of this long block are:
- Callico coated Clevite bearings
- Billet double chain timing set
- Manton pushrods with upgraded tips
Drag & Drive cars put on a lot of both road miles and track passes. We offer two upgrades for enhanced longevity. First is upgrading the Jesel rockers from aluminum to stainless steel. The second is switching from bronze roller bearings in the lifters to DLC-coated steel (diamond-like carbon). These changes reduce wear which in turn reduces the need for valve lash adjustments. You can request either or both upgrades. See more about the lifter options in the video down below.
We strive to keep the required components in stock and the lead times short. This is a long block used on a lot of our builds so it is often on the floor and available for immediate shipment.
This is the long block that powered Rob Carter (Bereyt Racing) and his LS-swapped VW Passat to 1st Place Street Eliminator finishes for both the FIA European and his home UK Nationals (see Note 4). He was running with conventional (Cometic MLX) head gaskets at 35 psi boost (max rating). Check out the video for more details. Nick Cryer won Sick Smokies (2025) and finished 2nd in SIck Week 2026's Unlimited Class in his 1933 Ford Coupe with a very similar build using copper head gaskets.
Click BUY NOW for more detailed information on our website. Please give us a call to ask questions, price some custom options or get one started. 815-725-2727.
Notes:
1. The long block is not pollution control and may not be legal for transportatin in your vehicle.
2. Pricing shown is for the convential head gasket variant with Jesel aluminum rockers and bronze lifter bushings
3. Photoset includes completed engines for illustrative purposes only. Additional components are not included.
4. Rob's long block used an SHP Pro block. These are no longer available. A key benefit of the Pro block was it came equipped with main studs. We replace the main bolts on the SHP with main studs.
BUILT BY PEOPLE WHO LOVE MOTORSPORTS FOR PEOPLE WHO LOVE MOTORSPORTS
