Fits 331 / 365 / 390 / 429 Series Blocks. 1960s 331 / 390 / 429 Exhaust Bolt Kit (3/8" UNC Parts). CAD-1 Cadillac V8 Exhaust Manifold Bolts - Version 1. Supplied With Stainless Steel Plain AND Spring Washers (As Pictured).
eBay