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Summit Racing

Cast Iron Engine Block, 4.125" Bore

$3,349.99 $3,313.43 Save $36.56

SKU: SUM-150216

In Stock
In Stock
Ships by Sep 13
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Professional / shop required

Overview

It features a standard deck height of 9.240 inches and an initial bore of 4.125 inches, with a maximum bore of 4.185 inches. This aftermarket block is cast in Germany from a Class 35 iron alloy for high tensile strength and hardness.
Show original supplier description
The Summit Racing SPC Pro LS Block is a new, heavy-duty aftermarket V8 engine block engineered for street, performance, and competition applications. Cast in Germany at a Tier 1 OEM foundry using brand new molds, it is constructed from Class 35 iron alloy, offering higher tensile strength and hardness than competitors' Class 30 iron. This bare engine block features a standard deck height of 9.240 inches and an initial cylinder bore of 4.125 inches. The bores are intentionally shipped 0.005 inches undersize to allow for proper honing to achieve precise piston-to-wall clearance. It is designed with a 6-bolt main bolt style and a 6-head bolt pattern, suitable for Gen III/IV LS Chevrolet engines. The block includes nodular iron main caps with fasteners and is designed for a 1-piece rear main seal. Its priority main oiling system and Siamese cylinder bores contribute to robust performance.
Vehicle Symptoms
  • Loud knocking noise from engine
  • Overheating and coolant loss
  • White smoke from exhaust
  • Metal shavings in engine oil
  • Low compression on multiple cylinders
Relevant Conversations
  • LS engine knock after overheating fix
  • cracked engine block symptoms
  • Summit Racing SPC Pro LS block review
  • 4.125 bore LS block rebuild
  • engine block replacement cost
  • LS block vs Dart block
  • engine knocking noise diagnosis
  • best LS block for 1000hp
  • LS engine swap block options
  • how to tell if engine block is cracked

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandSummit Racing
Part NumberSUM-150216
CategoryEngines and Components

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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