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DART LS Next 427ci 9.240 Deck LSX Stroker Short Block

Our DART LS Next Race 8 Second Dart Short Block is designed for vehicles looking for a strong foundation for high horsepower. This short block is professionally internally balanced within one gram and ready for your big horsepower street or race car. The extra strength of this setup relies upon a SCAT 4340 forged steel crankshaft and set of SCAT 4340 forged steel H beam rods, with arp2000 capscrews, along with the Dart LS Next splayed 4 bolt main LSX block. All of the LSnext blocks are based on Gen III LS design, but can also be used in newer applications. This is the premium 4 bolt iron block available for LSX based motors and can handle upwards of 1500hp. The included components are safe and reliable for up to 1000 bhp, for higher horsepower applications or heavy boost/nitrous use we have upgrades to better pistons, rings, rods, crank etc. Don't hesitate to ask us about custom internal parts for your exact needs, wants, and application!

Long Blocks: There is a $200 charge to assemble anything else you buy from us to your short block. Please ask if you are interested in anything you don't see!
Availability: All Short Blocks are custom built and take 4-6 weeks to build.
Shipping: All Short Block builds are charged the actual cost of shipping which is calculated and charged after you make your order, plus a $45 crating fee.
Was: $6,299.99
Sale: $5,899.99
Save: 6%
Save: $400.00



Block: Dart LS Next 4 bolt main iron block, 4.125" bore, 9.240 deck height, race prepped and machined

Crank: SCAT 4340 Forged Steel 4" stroke, for 24 or 58 tooth reluctor, 6 bolt flywheel (8 bolt available, Neutral balanced with the rest of the assembly

Rods: SCAT 4340 Forged H beam 6.125" with arp2000 capscrews

Main and Rod Bearings: Clevite H Series, ms2321hx mains, cb663hn rods

Cam Bearings: Dart Coated

Pistons: CP bullet series flat top 2618 forged pistons, -1.4cc valve relief

Rings: CP rings, steel top, file fit to application

Dart LS Next Short Block Options:

CP dish pistons: Cp -17.4cc dished pistons. $50
Wiseco dished pistons and GFX ring set: -20cc or -32cc dished pistons. $150
CRANK AND RODS: Callies Compstar Crankshaft with billet reluctor wheel installed and H beam rods w/arp2000 capscrews $350
CRANK AND RODS: Dart Billet CCW 4" stroke crank and CP bullet rods w/wmc capscrews good to 1500+hp $1360
WRIST PINS: Tool Steel .200 wall thickness for 1200hp+. $200
FLYWHEEL: SPEC SFI Legal Billet Steel Flywheel. $249
FLYWHEEL: SPEC Lightweight SFI Legal Billet Aluminum Flywheel. $379
BALANCER: Romac SFI lightweight steel/aluminum balancer. $499
OIL PAN: Canton DART LS NEXT Drag Race Front Sump Oil Pan and Pickup Kit, part numbers 15-286A and 15-287. $949

Dart LS Next Block Specs:

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.

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 aluminim, or optional Darton 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.

DART LS Next Block 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


  • Dart-LS-Next-Stroker427
  • Dart-LS-Next-Stroker427
  • TREperformance
  • All Short Blocks are custom built and take 4-6 weeks to build.
  • New

Shipping Information

  • Item Requires Shipping
  • 250.0 lbs.
  • W36.0000” x H15.0000” x L36.0000”
  • This item will require a special quote for shipping charges.
  • All Short Block builds are charged the actual cost of shipping which is calculated and charged after you make your order, plus a $45 crating fee.

  • Have a question? Ask the Pros
  • 877-514-9494Mon - Fri 8:00 AM - 4:00 PM PST