The Melling M355 pump is a standard pressure, standard volume pump that is considered a suitable replacement for the factory oil pump (GM part # 12571885) and offers improved resistance against cavitation at higher RPMs. The cast aluminum housing is CNC-machined and hardcoat anodized. The cast iron cover is CNC-machined and phosphate coated. The relief valve features a screw-in valve plug. The factory LS oil pump suffers from cavitation above 6,200 RPM, which results in a drop in oil flow of nearly 1 GPM by 7,000 RPM. This cavitation can also aerate the oil, which causes drops in oil pressure and can result in oil starvation. This is why we do not recommend shifting any higher than 6,200 RPM with a stock engine. Engines that run at RPM's above 6,200 should use an upgraded Melling pump to prevent these issues. This pump is suitable for engines that feature Active Fuel Management (AFM). Engines without AFM/DOD should use a lower flow pump. See Melling p/n 689-M295, 689-10295 or 689-10296.

Features:

• 43 PSI Pressure Relief Valve Spring
• 1.28 Displ (cuin/rev)
• The cast aluminum housing is CNC machined and hardcoat anodized
• The cast iron cover is CNC machined and phosphate coated. The cover also features countersunk screws for more timing cover clearance.
• The relief valve features a screw in valve plug with the optional lower stock pressure spring supplied
• Compatible with factory GM oil pickup tubes

Fits GM LS and Vortec engines that feature AFM/DOD Applications:

• Vortec 5300 LS4, LH6 2005-2006