Quote:

So you guys don't like the Isky RAD-9999 springs for these heads?

Specifications:
Style: Dual with Damper
Outer OD/ID: 1.600"/1.150"
Inner OD/ID: 1.040"/.745"
Seat Pressure: 250 lbs. @ 2.000"
Open Pressure: 770 lbs. @ 1.200"
Rate: 650
Coil Bind: 1.150"
Max Lift: .800"

They are 283 @ 1.950 and 7838 @ 1.250



I'm sure they're great but when Dwayne Porter spec'd my cam he recommended a spring similar to the Comp 943-16 around a 550lb spring rate so, I chose the TFS-16943-16 (PAC-1243). Plus, I wanted to run locators and standard height retainers and locks and with this combo it ended up scary close to the spec'd 1.90000 installed.

By the way FWIW I'm running these heads OOTB out of the box. No port work, clean up or valve job. I was tempted to at least clean up the cast flashing but, wanted to know what they would do truly OOTB. I checked factory valve contact with Prussian blue, assembled and bolted 'em on. Well, I guess I did fix the center rocker stands so maybe OOTB "flow-wise". Car with me is 3785 and has gone [Email]10.33@130[/Email] in good air. I'm sure I'm leavin some on the table but does OK for now. More info on engine combo about half way up the page