Will these bolt directly to my engine without modifying the exhaust system downstream?

These mount at factory locations using existing bolt holes. You'll need to verify your current exhaust piping aligns with the header outlets—if your system uses a collector or crossover, confirm clearance or plan for pipe routing adjustments.

Do these require any prep or finishing before installation?

Stainless headers ship ready to bolt on—no painting or surface prep needed. They're finished as-is and will develop a natural patina over time under heat.

What do I need to seal the header-to-engine connection?

You'll need new gaskets rated for your LA small block configuration. Use high-temp gasket sealer or copper sealant on both sides of the gasket, then torque bolts according to your engine's service manual specs.