Trick flow heads: different installed valve height
And just a word of caution...I know everyone says they'll get their heads checked, and I know TF are some of the nicest OOTB quality-wise...but their spring specs as-tested do not match the paperwork specs. At least on the BB heads. So if you are buying check (or have your shop check) specifically the pressures and installed spring heights on every valve. It's more time for sure, and I guess it all depends on how nitpicky you are with this stuff but I found them all slightly different and they will need correcting. Not valve stem height but spring height which = pressure.
Okay so this thread was a month old...dammit!:rolleyes: