ProComp/Speedmaster aluminum heads

The reason I bought them bare this go around is that I tested their valve springs on a spring tester I have in the garage....not a big dollar one...but I was getting about 270 psi at .600 lift....i dont remember the seat pressure. I prefer to use the PAC 1903 spring....140ish at 1.80...and 350 ish over the nose...they are about 100 bucks for a set.