Before deciding on whether or not spring shimming is necessary....... go to the spring page on the TF site and look up the specs(TFS-16094).
You’ll see they don’t agree with the paperwork that comes with the heads........ but they do agree with the specs that the spring manufacturer shows for that spring(PAC 1294).
On my tester, the springs match the PAC specs.
Thanks for that, totally doesn't match what the tech guy emailed me, but it's impossible to argue with the info right from PAC's website plus your test data!
If I'm doing the math right, at 1.95" installed height, that would be 153.6# on the seat and 406.1# open, which sounds like more than enough spring rate and I definitely shouldn't shim them, if anything it might be too much spring.
