[Luke]

For most vehicles there is no “recommended” interval for valve cover gaskets just as needed. Like you I’ve had a few 200k cars with the original gasket.

[Luke]

Depends on the vehicle. Most newer vehicles have coil on plug so the tune up generally only consists of spark plugs. Although that could be pricier on newer vehicles due to the manufacturer recommending and using platinum and iridium plugs. However on some older (2000 on most Honda’s)it may consist of spark plugs, plug wires, cap, rotor and check ignition timing. Even older vehicles all that plus replacing points, adjusting carbs, etc.

[Author]

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