135# is a number in a book. Put them on the spring tester then you will see and take into account a valve job which changes the protrusion slightly. Used springs actually take a .030 shim to get there most of the time here.
At 1.80 they go up to 145#, seat, which is what I get when I use them in EVOS and early TC motors with retainers I made.
John
Certainly not saying you are doing anything wrong. I respect your opion and work. I just have good luck with the TW5-6 and the 7mm heads with stock springs. When I did it I was told I was nuts by many, but now have several out there and they are working well. I would not expect the same noise level from all builds and valve / spring setups.