Will these headers work with my factory exhaust manifold gaskets?

Check your current gasket thickness before installation. Header gasket material and dimensions aren't specified in the product data — bring your old gaskets to the parts counter or test-fit the headers dry first to confirm fitment.

Do I need to tune my engine after installing these headers?

Headers alone won't require a tune on a naturally aspirated motor, but if you're also changing the intake, carb, or cam, a baseline dyno run will tell you if the air-fuel ratio needs adjustment.

What's the warranty on stainless steel headers?

Warranty details aren't listed here — contact ModSupply directly for coverage specifics and any return window on this product.