5.9 stroker build
Double check those numbers. Here's what the specs say in the instructions. I know my TF heads (setup for hyd roller cam) and they were indeed setup for an installed height of 1.950". Not sure if they use +.050" keepers or what.
View attachment 1716376966
I caught some discrepancies in TF's specs, depending where one looked. The 150# seat pressure was given to me by Jeff; there is no reference to seat pressure in any TF literature. I them asked him why the instructions state 138# seat pressure. He said that when the springs are installed on the head, they're compressed about 0.050", increasing the seat pressure.
Below I copied the specs for the 16094 springs from the TF website:
Brand: Trick Flow Specialties
Manufacturer's Part Number: TFS-16094-16
Head Part Number: 61417802-C00
Product Line: Trick Flow® by PAC Racing Dual Valve Springs
Valve Spring Style: Standard
Number of Springs Per Valve: Dual
Maximum Valve Lift (in.): 0.625 in.
Spring Rate (lbs./in.): 427 lbs./in.
Coil Bind Height (in.): 1.190 in.
Seat Pressure (lbs.): 150 (I added this line for my own reference)
Retainers Included: No
Outside Diameter of Outer Spring (in.): 1.550 in.
Inside Diameter of Outer Spring (in.): 1.130 in.
Inside Diameter of Inner Spring (in.): 0.757 in.
Damper Spring Included: Yes
Locks Included: No
Valve Stem Seals Included: No
Valve Springs Coated: No
Remanufactured: No
Quantity: Sold as a set of 16.
Notes: Up to .625 in. lift @ 1.900 in. installed height.
A few things that stand out: the last line references 1.900", but only .625 lift. The instructions say .680 max lift. The spring rate is different between the instructions and the spring specs.
Later I'll go out to the garage and measure the springs with my calipers.
The 138# is a touch lighter than Hughes' spec, while the 150# is slightly more. With the high spring rate, the over-the-nose pressure catches up and surpasses Hughes' spec, no matter which combination of TF's specs are used. I went over the cam card specs with Jeff and he assured me that their springs are right in the ballpark of Hughes' requirements.