PRI 2019: Choose ProMaxx Performance For All Your Cylinder Head Needs While at the ProMaxx Performance booth at the 2019 PRI Show, we learned this cylinder head company has options for everyone. Whether you are looking for a set of as-cast or CNC-ported heads for your small block, big block, or LS engine, Promaxx can hook you up. Even if you're looking for OE replacement or diesel-engine heads, ProMaxx carries a wide range of cylinder heads for almost any engine. Isn't it time to check out Proma