On the new Victor MW heads, PAC 1326 Springs with PAC retainers and spring locators that were only 0.030" thick vs, the standard 0.060" thickness
2.00" Install height.
My old Victor MW heads had the spring seat cut. I don't recall how much, but tried cutting the spring seat a bit more and ended up breaking through (hard to detect it was very small) into the port at one edge.