Speedmaster®
Pontiac 455 4340 Forged Steel Crankshaft ST-4.25 M-3.25 RJ-2.200 RMS-2Pc Ext
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Product Information
Overview
These Speedmaster crankshafts are made from the same strong aircraft-quality forging as standard-weight cranks, but have profiled counterweights for less weight. Speedmaster lightweight crankshafts are perfect for engines wanting quicker rpm. These crankshafts feature profiled aero-wing counterweights and have straight shot and chamfered oil holes. Speedmaster crankshafts are nitride-hardened, with large radii on all journals for superior wear resistance, and use lightening holes in all rod throws.
Specs
| Brand: | Speedmaster |
| Part Number: | PCE276.1140 |
| Part Type: | Crankshaft |
| Product Line: | 4340 Forged Steel |
| Rear Main Seal Style: | 2-piece |
| Engine Stroke (in): | 4.250 in. |
| Crankshaft Material: | Forged 4340 Steel |
| Engine Balance: | External |
| Lightened: | Yes |
| Requires Narrow Bearings: | See notes below |
| Rod Bearings Included: | No |
| Main Bearings Included: | No |
| Rod Journal Diameter (in): | 2.250 in. |
| Main Journal Diameter (in): | 3.250 in. |
| Minimun Rod Length (in): | 6.700 in. |
| Balancer Bolt Thread Size: | Standard |
| Crankshaft Snout Style: | Standard |
| Quantity: | Sold individually. |
| Notes: | Check the bearing to crank radius clearance. Rod bearings may need to be chamfered or alternatively use narrow rod bearings. |
| Tool: | Stroker Combinations |
Warranty Information
12-Month Limited Worldwide Warranty
Prop 65 Warning
This product may contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.
Installation Guide
Our AI assistant generates a step-by-step guide for this product — covering installation, maintenance, and troubleshooting.
This AI-generated guide is for general reference only and does not constitute official Speedmaster product documentation. Always verify fitment, torque specifications, and safety requirements before installation.