I bought my EZ heads direct from Indy at a car show and my heads have comp 928 dual springs with damper rated to .650 lift.
I had a shop look the heads over and they tested the springs at 160 pounds seated (1.925" installed height) 335 pounds 500 lift and 380 pounds 620 lift and coil bind at 1.150 (775 lift).
'68 Coronet 500 w/ Indy EZ-1 headed 446, 727 trans, 9" rear
First day at the track with SUV street tires and no traction: 1.688 60', 7.24 @ 101.79 in the 1/8 mile
Great customer service from: DominicThumper Carbs, B3 racing engines, Porter Racing Engines, A-1 torque converter's, Quick Performance, Racer Brown Cams, R&R Performance, Manton pushrods
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