Stock Mercury Replacement Aluminum Exhaust Kit - Big Block Chevy

These stock replacement aluminum manifolds use “LPC” or “Low Pressure Casting”. LPC is a casting method that uses the pressure of inert gas to force the molten liquid metal from the bottom of the holding pot through a riser pipe into the tooling mold directly above. After the casting cools and solidifies, the pressure is reduced. The pressure applied usually does not exceed 1.0 bar, hence “low pressure casting”. The technology of “Lost Foam” casting is carried out by gravitational force (0.0689 bar, 1 atmosphere pressure) while LPC is done by pressurizing the molten liquid metal, usually at around 0.3 ~ 0.8 bar, 4.35~11.6 atmosphere pressure. LPC can be carefully controlled to eliminate porosity in the casting wall. This is because the molten metal becomes denser as it is squeezed into the mold by pressure, thus preventing gas bubbles and inclusions. The results are as superior as those produced by forging (manifolds can not be produced by forging). The LPC method allows for improved filling of thin-walled parts and large areas of tooling.

This is a complete kit with all the bolts and gaskets needed for assembly. The manifolds and risers are constructed from 356-T6 aluminum and powder-coated black. Replaces Mercruiser #807078T10 and 89011A8 Manifolds, and #807988A03 and 44354A3 Risers

Stock Mercury Replacement Cast Iron Exhaust Kit - Big Block Chevy

This is a complete kit with all the bolts and gaskets needed for assembly. The manifolds and risers are cast iron. These are patterned to be Mercury replacements for 4" exhaust connection. Replaces Mercruiser #807078T10 and 89011A8 Manifolds, and #807988A03 and #44354A3 Risers