i bought a set of comp valve springs from a company for my 6l(not bashing im just informing) this company said they were direct fit!! well we checked to make sure that we would be able to get the seat pressure that was advertised on the box which would be [email protected] installed height! well the 6l valve spring has a installed height of 1.8. this spring if it was just install assuming that it is a direct fit spring is going to have no more spring pressure at 1.8 than stock!!! you need to shim this spring .204 to achieve 120 psi of seat pressure. bolth the comp spring as well as the stock spring have 90ish psi of seat psi at a installed height of 1.8. make sure you shim this spring so you are increasing psi. i called the vendor back and told them this,and they said oh yeah they do need to be shimed!!!! beware of this
Shimming springs is part of the game. If the spring drops in, that is direct fit to me. Did the seller tell you they would have specific seat pressure at the factory installed height, and they don't? I appreciate you posting the info up about the installed height for guys to look at and help them. But I don't see where the vendor did anything wrong or misinformed you based on your first post.