Application Fitment: Designed for 1987-up small block Compatible with Chevy heads using tall centerbolt valve covers for a clean, secure installation Thread Specifications: 1/4"-20 thread pitch ensures proper engagement with factory-style cylinder head mounting points Precision Dimensions: Measures 5.13" overall length with a 4.88" under-head length and .50" overall diameter Quality Construction: Polished stainless steel offers long-lasting durability and an attractive, finished appearance Fastener Design: Countersunk Allen head provides a flush fit and clean look while allowing easy installation and removal For 1987-up small block Compatible with Chevy heads with "tall" valve covers. Item DetailsCountersunk Allen Head