Dart 427ci short motor - assembled
The factory GM LS engine block is an astounding thing, back when the LS1 came out it was said that the block was good for 500hp, anything over that and you’re rolling the dice and the stakes were high! 500hp came and went very quickly and today, standard bottom end (SBE) LS engines is its own drag racing class and with some crazy boost control, exotic race fuels and full on race chassis, they are running into the 7’s over the ¼ mile… astounding!!
So, why build an engine, and even more whys do I need to change the block? Building a SBE race motor that’s designed to do around 10-15 miles total in its whole life is one thing, building an engine that will do 60,000+ kilometres reliably is another. While the factory short block is amazing - as discussed above, it is far from indestructible. A good set of conrods, a steel crank and forged pistons can only do so much and if the block starts to move around or it splits a bore, expecta big repair bill and the chances are that your good crank, conrods and pistons are now junk.
Enter the Dart SHP LSNext Iron block, from Dart Machinery. Richard Maskin founded Dart in 1981 in a two-car garage in Michigan, USA. In the years since Maskin started his business with a desk and a telephone, Dart has become the proven leader in aftermarket cylinder heads, intake manifolds and engine blocks. The SHP LSNext iron block is rated to 1500hp but just like the LS1 in 1999, the rating does not give a true indication of what the block is capable of supporting. And if you need more piece of mind than that, we can offer the SHP LSNext Pro that is made of a superior iron compared to the regular SHP LSNext.
We recommend replacing your aluminium LS block at or around 900hp flywheel (500kw at wheels).
Package Includes
1 x Machining, balancing & assembly
1 x Dart SHP LSNext Iron cylinder block (inc parts & fastener kit)
1 x CP Bullet 4.125" Pistons & Rings
1 x Compstar 6.125" H-beam Xtreme Rods
1 x Compstar 4.00" stroke 8-counter weight Crank
1 x ARP Dart 4-bolt Head studs
1 x Set of Main Bearings
1 x Set of Big end bearings
1 x Set of Cam bearings
1 x Gasket, seals as required
1 x Cometic head gaskets
1 x GM oil pump - High Volume
1 x Machining & balancing
1 x Engine Short motor assembly
Key Features
- Dart priority main oiling system with provisions for stock oil filter mounting
- Accepts factory and aftermarket oil pans
- Siamese cylinder bores with thick walls
- Cylinder barrels extended .375in at the bottom of the bores
- Thick decks ensure reliable head gasket seal
- Blind head bolt holes available in 7/16in or 1/2in
- 6-bolt per cylinder capability
- Scalloped water jackets increase flow around cylinders for better cooling
- Clearanced up to 4.100in stroke w/ steel rods
- Clearanced for center counterweighted crankshafts
- Splayed outer bolts on middle main bearing caps
- Provisions for LS2X roller lifters and cam
- Uses OE front and rear covers
- All OE bolt holes for starter, water pump, etc
We also offer Higgins Race Heads 6-bolt LS3 / LS7 style cylinder heads for maximum performance and cylinder head sealing.