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Manley 290730X SBC 355 Rotating Assembly 3.480 Stroke 4.030 Bore with X-Series Bearings

Manufacturer

Picture for manufacturer Manley

Part Number

290730X
7 reviews
Sale Price

$2,887.89

Estimated ship date Thursday, November 19

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Product Details

The Manley 290730X is a complete Small Block Chevy rotating assembly engineered for the 355 CID displacement configuration. Built around a 3.480-inch stroke and 4.030-inch bore, this kit delivers a drop-in foundation for high-performance street and race builds. The "X" suffix designates the inclusion of Manley's optional X-Series rod bearings, which feature an additional .001" of extra clearance for applications requiring tighter tolerance control.

Key Features:

  • Lightweight 4340 forged steel crankshaft — heat treated, stress relieved, shot peened, nitrided, and 100% Magnafluxed for maximum durability
  • Micro-polished large-radius journals for reduced friction and improved bearing life
  • Pro Series Lightweight I-Beam connecting rods supplied with 7/16" ARP cap screws (ARP 8740 standard; ARP 2000 optional)
  • 2618 forged aluminum Platinum Series pistons with premium Chrome Moly wrist pins
  • High-performance piston rings included
  • Clevite "H" Series narrowed rod bearings and "P" or "H" Series main bearings included
  • X-Series rod bearings with .001" extra clearance (designated by "X" suffix in part number)
  • Rated up to 900 HP with ARP 8740 and up to 1,500 HP with optional ARP 2000 cap screws
  • 3.480" stroke / 4.030" bore configuration produces 355 cubic inches
  • Compatible with standard deck Small Block Chevy blocks

Note: The 350 and 400 Small Block rotating assemblies in this series are shipped unbalanced. For a precision-balanced assembly, order balancing service part number 04000-1 separately. Manley crankshafts are not intended for use with highly boosted roots-style cog belt superchargers.

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My first order from THMOTORSPORTS so far has been great. I will happily rate it again after receiving the part.

Great checkout

I was not able to reach a live person to ask a question so I googled my question and was able to get the information I needed to order the correct item. The process to order was quick and easy.

Finding the part was super easy and simple. The only issue I really had was the delay in the shipping. I paid extra for faster shipping and it still took over a week to get to me. When I tried contacting them through the chat I never got any feedback after asking questions just a "let me check that for you" then chat ended. I finally decided to email and then I got a reply basically saying the same thing. Correct part did wind up showing up without tracking update(kept showing sent to warehouse).

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