Header

iTrader: (7)

OK so I’ve had this cam sitting around collecting dust for 6+ months so it’s about time put it in the Z06 just need some valve springs. Cam specs are 23x/25x .660"/.660". So far springs I'm considering are:

1. Cam Vendor’s Springs .675" max lift (no specs available for open/closed seat pressure), $365 + shipping.

2. Patriot Gold Extreme .660" max lift (Spring Pressure Closed: 155 lbs. @ 1.800" Spring Pressure Open: 410 lbs. @ 1.140"), $275 + shipping.

3. PRC EHT .675" max lift (Spring Pressure Closed: 161 lbs. @ 1.800" Spring Pressure Open: 472 lbs. @ 1.150"), $350 shipped.

I'm leaning towards the PRC's, but looking for some opinions. The Cam vendor won't give me any info on their spring other than "That's what we recommend & nobody else's will last as long as ours". Another local C6Z owner had some issues with the springs that Cam vendor used on his car (torn up valve seals after 4K miles). Vendor claims they've since changed spring manufactures, but won't give me any specific info so I'm hesitant. Patriots have been the spring of choice for the majority of my local LSx crowd & they are cheaper, but I'm a little concerned about running at the high end of what they say max lift is (.660 lift cam vs .660 max lift spec). Also Patriot seat pressures are just a little lower than the PRC's. Opinions?

Also curious about reusing the stock LS7 3/8” pushrods w/the cam listed above. Cam vendor claims stock pushrods are all they use on all their customer cars. Mine have about 20K miles on them. Thanks.

ramairws6

iTrader: (33)

I've been running the Patriot Extreme spring and stock LS7 pushrods on my 441 now, 3 years and no issues at all. Cam is also in the 660' lift range...

ringram

Good to know. What lifters?
This is my exact combo. Comp LSR cam and Patriot Duals. 0.660 lift 227/243-113 cam though. Mild, for the 4000lb sedan.

Sales2@Texas-speed

iTrader: (5)

Seems like a no-brainer in the regard to the 'no spec" springs (that's along the lines of buying a camshaft without knowing the specs IMO, and I would never do it)!

With the big valves in the LS7 heads, even the titanium intakes, I'd definitely recommend the PRC's for that extra pressure and life-span as compared to the other competitor's.

Beau@SDPC

iTrader: (14)

Installed height on the LS7 is not 1.8. Unless you plan on shimming the springs to 1.8 make sure to compensate for the taller installed height. Then your .660 spring will effectively gain more lift capacity but at a lower closed pressure. Or if you are using shorter valves or have compensated in some other way.

Header

iTrader: (7)

So these would need to be shimmed 0.160" to make up for the difference in installed height (1.800" for LS1 vs 1.960" for LS7) correct?

Beau@SDPC

iTrader: (14)

You are correct on that unless you wish to gain more form the lift of it being at a taller installed height, and just shim to get a better amount of seat pressure.

The EHT spring should work well being that it should take more abuse from the valvetrain over time and still retain a good amount of pressure.

Sales2@Texas-speed

iTrader: (5)

Like John said, always a good idea to get the extra pressure back by shimming. Those springs coil bind at about 1.060".

BTW, the .675" lift EHT springs can also be purchased, along with the rest of the PRC line-up, from our friends at Scoggin Dickey as well!

ramairws6

iTrader: (33)

I've been running the Caddy liftrs with no issues but have heard alot of horor stories. So i've been crossing my fingers.........

ringram

Yeah I had a horror story. Lifter either turned or seized, trashed the cam and lifters and mains! Rebuild time. I think link bar lifters are the go. Maybe Morel's

ramairws6

iTrader: (33)

Were you running the Caddy lifters too? Ya, i would honestly go with the Morel's........

ringram

stock LS7 I believe