My plan for my lq9 is just to turbo it with s475. No cam swap, just springs. I heard than PSI maxlife springs are good, not sure where to get them. Any suggestions on most economical springs that are sufficient for this build.

Thanks

 

These are certainly economical. Not sure if anyone has tried them yet.
http://store.speedmaster79.com/show...dual-valve-springs-140lbs-1800-1180-coil-bind

A quick search turned up the PSI springs.
http://usaperform.com/valve-spring-life-ls1ls6-replacement-springs-1290-beehive-lift-1800-p-969.html

I've never heard a bad word about PAC 1218's either.
https://sdparts.com/details/pac-racing/pac1218

 

Lots seem to like the PAC's on small cam boost setups. I ran them on my old N/A383 LT1 with a decent size cam 234/237 .577ish lift IIRC . They worked well and fixed the valve float issue it was having on the dyno with COMP 918's. Actually picked up 60whp bc of float!

If you are gonna stay stock cam I would recommend those. If you are gonna be tossing in an aggressive ramp cam later I would suggest a set of BTR Duals for not much more. I ran them on my vette as well as just bought a set for my 5.3L LS6 cam turbo motor I'm building. I like the peace of mind of having a dual spring. Plus by the time the motor gets in the car it will probably have a custom spec cam.

Jay

 

1218's are what I used to 25lbs with the ZR1 cam. It's more aggressive than an LQ9 cam as well. I upgraded to 1518's and a bigger cam this year.
http://www.briantooleyracing.com/600-lift-pac-1218-beehive-valve-springs.html



Pretty competitive prices here.

http://www.briantooleyracing.com/springs.html

 

+1 on the brain tooley springs