4P Pro 156v2 CNC Head Stroker Kits The 4P valve spring micrometer

The 4P valve spring micrometer is used between the seat base in the head and the retainer to get a quick and accurate measurement of your valve spring installed height

Change bore sizes in seconds

Dyno Tests shown are a built block with 12

This uses a 102mm Crankshaft

Allows for 2 extra quarts of oil

4P Pro 156v2 CNC Head Stroker Kits The 4P valve spring micrometerThe NEW Pro 156v2 CNC cylinder head is the ultimate cylinder head for your street car. The original Pro 156 raised the bar and set the standard for entry level street cylinder heads by offering the highest quality in the industry and airflow that surpassed many very expensive race heads. The newest version of this head takes it a step further with improved airflow throughout the entire lift range, top to bottom. We spent countless hours balancing