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@Schurkey said, that would depend on the year and engine and is it just valve stems seams or guides that helped damage the seals. Typically when you see the start up smoke, if it is just the seals, you can also see it when you accel hard enough. My girl's 1990 K2500 5.7 has the start up smoke and also the accel smoke but the accel is not as bad as the start up. I have new v/c gaskets and the sets of exhaust seals and intake seals but I know I need to check for slop at the guides while I am in there. Luckily, the engine only has 130k miles on it, so I might get lucky. She and I have only been adding about 1/2 quart of oil between 6 month changes. Does not put enough miles on it to change every 3k-4k miles. I also know that the catalytic converter is original. She has a small exhaust leak at the front and back of muffler. After I do the seals, we may be selling the truck because I am getting a new to me GMT800 K2500 pickup. Decisions....decisions.....
