kyhunter89

ls6 yellow springs safe to run? Says safe to .550 lift and cam is .551".
noob question.

It'll be a 04 5.3. 706 heads, full bolt ons in a 00 silvy

trans_am7935

iTrader: (15)

well let me give you an example, the LS6 cam shaft has a lift of .550 on the dot for both lobes, i think you will be just fine.

dkota1968

iTrader: (1)

Lingenfelter actually says they are good (ls6 springs)til .575 lift. They sell a package deal with a cam, gt2-3 with 570ish lift. I had that package in my old truck and ran great but it was nothing more than a lil crazier than a 04' ls6 cam. However ive been recommended with the newer style cams like the tr220 to run a pac or comp 918 spring because of the agressivness of the lobes. It will probably work for a lil while but the others would last way longer. im shure more will chime in. I wouldn't cheap out on springs because they save your valvetrain and they are harder to put in on car than the damn cam haha.

disc0monkey

iTrader: (10)

i think the ls6 spring features a less brittle/softer metal than a 918, that being said if the LS6 can safely control the valves on the TR220 they should last longer than the 918. like mentioned above Lingenfelter has been pair them up with their GT2-3 which I have seen spec'd up to .581.

Always2Slow

iTrader: (8)

Do not use ls6 springs on anything but the ls6 cam or other stock cams. Lobe lift is one part of the equation. The other part is ramp rate aka how agressive the lobe is. If you want a quality beehive spring pac 1518 will last you a long time with that cam or you can save some money and get the 1218s

kyhunter89

The ramp rate is what worries me. It even says good to .550" with less aggressive rates and the tr220 is aggressive, yet I seen youtube videos of people running the setup, but have no long term feedback.

PREDATOR-Z

No, lift is not the only way to match springs, seat pressures are very important (related to ramp rates)

kyhunter89

I understand that, but theres not a measurable guideline to follow... So I must ask questions.

180ls1

iTrader: (4)

not always true, the ramp rate is more important along with other things, now the heads will have smaller valves which is easier to controll but i would not risk it. I would run some 918's at the least.

PREDATOR-Z

yes there is a measurable guideline, I gave it to you, 'seat pressures' requirements.
I would personaly run PAC 1518 beehives. Comp 918s will work but eversince they changed manufacturer, the quality is not as good as in the past.
In any case, it is very important to install the springs at proper height to ensure they perform as designed.You need a spring micrometer for measuring install height.
Also never just start and go, always let the engine warm up to operating temperature before you go high in rpms. Aftermarket springs are more brittle and need to warm up.

01ssreda4

iTrader: (96)

As Predator stated, go PAC 1218s or 1518s.