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Vehicle Info NeededLS Next Engine Block Cast Iron 4.125 / 9.240
Ships on 01/21/2027
Lowest Price GuaranteeDesigned from a clean slate approach the LS Next Iron block has addressed the shortcomings of the LS platform and is the ideal candidate for hot rodders, drag racers, circle track competitors, off-roaders, and high performance marine enthusiasts.
By utilizing conventional style main caps and oil pans with LS rotating assemblies and related components, Dart has addressed the windage and oil control problems which result from the factory LS engine’s separated crankcase bays.
Features:
- Priority main oiling system
- Siamesed cylinder bores with extra thick walls
- Cylinder barrels extended .375" at the bottom
- Extra thick decks ensure reliable head gasket seal
- Blind head bolt holes don’t go through to water jacket
- Scalloped water jackets increase flow around cylinders for better cooling
- Clearance for 4.100" stroke w/ steel rods
- Splayed outer bolts on middle main bearing caps
- LS or Gen I style motor mounts
- Provisions for OE stock roller lifters and cam
- Uses stock timing covers and stock rear cover
- All OE bolt holes for starter, water pump, etc
- Driver or passenger side starter mounts
Emissions Note:
This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.
CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART
Dart Unleashes the Full Potential of the LS Engine Platform
With the LS Next Engine Block!
The LS Next block is the first significant change in the bottom end architecture of the LS engine platform. By eliminating the ''Y-block'' design and utilizing conventional style main caps and oil pans, (stock pans can be used with Moroso oil pan spacers) Dart has addressed the problems resulting from the LS engine's separated crankcase bays. Windage is greatly reduced, resulting in increased power and improved lubrication.
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This design change led to several additional improvements. The main webs are significantly stronger because the bay to bay breathing windows are eliminated in Dart's design. Deleting the windows also allows the cylinder barrels to be extended by .3750'' into the crank case, providing greater piston support at the bottom of the stroke. Two standard bore sizes are available, 4.000'' and 4.125''. Maximum bore of 4.220'' for iron and 4.165'' for aluminum, or optional Dart M.I.D. sleeve kit allowing up to 4.220'' bore.
All stock and aftermarket LS components can be utilized. Conventional style 4-bolt steel main caps are used. A 5/8'' thick full deck design is utilized for superior strength, with six head bolts per cylinder to provide secure clamping. Dart's priority main oiling system ensures high rpm reliability and includes provision for oil restrictors in the lifter valley.
Features:
- Dart's LS Next block is cast in the USA with premium cast iron alloy or aluminum
- Conventional style 4-bolt steel main caps with 7/16'' bolts are used
- Full main webbing for maximum bottom end strength
- Cylinder barrels are extended by .3750'' at the bottom, providing greater piston support for all combinations
- 9.240'' deck height, with options of 9.450'' are available which allows for a possible effective barrel length of 9.825'' deck block
- Extra thick Siamese cylinder bores allow for larger displacement capacity and a max bore size of at least 4.220''
- A 5/8'' thick full deck design with a 9.240'' deck height
- Six head bolts per cylinder provide secure clamping for power adder applications
- Head bolts are upgraded to 7/16" for increased strength
- Blind head bolt holes don't go through into the water jacket
- Provision for oil restrictors in the lifter valley
- Revised low restriction priority main oiling system
- Pro-Stock / Pro-Mod big block style stepped main oil galley
- An external oil filter must be used with stock or aftermarket oil pumps
- Dual starter mounts
- The water jacket on the #1 cylinder has been expanded for additional cooling capacity
- LSX style lifter bosses and dog bone provision are provided
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