Manley Performance 4G63 Spring & Retainer Kit for $249

SI Dual Springs w/ Manley Titanium Retainers for $325

Brian Crower 4G63 Racing Valve Spring and Titanium Retainer Kit for $209

I have made my mind up that I am going to change my springs and retainers when I have my Helix V2 cams installed. I feel the need to take my car past the 7000 redline. I don't know how much rpms the block can take so however much the stock EVO VIII block can take that is how high I want to be to go in the rpm range.

 

Whether you go single or dual springs depends on your ultimate goal for RPM capability. That will depend on how much you want to spend on your rods and pistons, though, as the valve springs are not the limiting factor in safely revving over factory redline. The forces on your rods and pistons increase dramatically with higher RPM.

 

So, how much can the stock block handle?

 

theres people that hit 8k on stock valvetrain w/ no problems but I wouldnt do this on a daily basis...lol

At the dragstrip I take mine to 6800-6900 when shifting from 1st to 2nd then 2nd to 3rd and 7000 for 3rd to 4th. this is all on the stock valvetrain, w/ 280's and the stock turbo