Improved Racing designed these crankshaft scraper and windage tray kits for direct bolt-on installation in 3.622″ and 4.0″ stroke LS engines, with either factory or aftermarket crankshafts and rods. These kits are compatible with most front-sump factory and aftermarket pans, such as the Pontiac GTO oil pan.
Improved Racing’s crankshaft scrapers help reduce oil starvation by closely contouring the crankshaft and rods to remove excess oil, ensuring oil is quickly returned to the bottom of the sump. Crank scrapers also help reduce parasitic drag and windage losses caused by excess oil on the crank, which reduces rotational mass and results in dyno-proven gains of 5-10 HP at the wheels.
Our scrapers are CNC-machined from 0.190″ thick, 6061-T6 billet aluminum. The crankshaft scraper kits also include an aluminum windage tray that is 10% lighter, 70% stronger, and provides more clearance for aftermarket rods than the factory windage tray. The included windage tray bolts directly to the scraper with self-clinching lock nuts instead of the main cap studs, allowing it to be installed without disturbing the scraper alignment.
The crankshaft scrapers and windage trays were designed in CAD software using actual GM part models, prototyped, and test-fitted for a completely bolt-on fit in every listed application. The factory oil pump pickup tube is kept in the factory location with no compromises or modifications required.
Crank Scraper kits are compatible with factory or ARP main cap studs. Reducer spacers as well as Class 10, flanged zinc-plated steel distorted thread lock nuts are included for use with factory main cap studs. For ARP main cap studs, use the nuts supplied by ARP.
Includes
- CNC-machined aluminum crank scraper
- Aluminum windage tray
- Self-clinching windage tray-to-scraper mounting hardware
- Flanged, locking scraper-to-main cap stud mounting nuts (for use with factory studs only)
- Reducer bushings for centering the scraper when using factory main cap studs
Technical Specifications
- Material: 6061-T6 aluminum (scraper), 5052-H32 aluminum (windage tray)
- Weight: 2.13-2.52 lbs (0.96-1.14 kg) (complete assembly)
- Does NOT fit engines with stepped main caps (Dart LS Next engines).
- These scrapers are not compatible with aftermarket crankshafts with center counterweights (8 counterweights). They are compatible with factory-style, 6-counterweight crankshafts only.
- Please use the crankshaft scraper application table to select the correct part number for your application.
- Oil pan must have a minimum depth of 1.70”, not including the gasket, to clear the windage tray. See image below for reference.

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