I just bought a new set of valve springs for my big block chevy with a flat tappet cam. These springs have 425 pounds pressure when open. Most of the springs I have run has been around 375 pounds when open. What do you guys think, will the flat tappet cam stand this much pressure with out wiping out a lobe?

I think you should use the valve springs the manufacturer of the cam recommends and sells. Then you should pray you don't wipe the cam out.

Come on guys, surely I can get more than one reply. I'd like to hear from some one who actually runs a flat tappet cam.

only one reply because its dead on. With flat tappet cam you need to run very close to manufacture suggestions,add zinc additive to oil if it does not have it and most don't now days. Flat tappets work fine when used as designed with loads used during design.

Look at specified springs and go from there.50 lbs open does not sound like much but its about 14% increase over your normal spring.

its been long enough my memory is failing me,but here is a thought i tink we ran 425 on ours,but,i also remember wiping lobes on startup.lol not a good thing.we would leave the inner springs out use the best lube we could get and breakin on low pressure and then put inners back in.you didnt list cam specs but less pressure may be safer.can shims be removed?

I always on start-up remove the inner spring and run the motor for about 20 minutes and then re install the inner springs. The springs are 425 pounds set up at 1.94. I am thinking about setting them up at about 1.99 or maybe 2.00. I wonder how that would effect the open pressure?

The real question is, what did the cam manufacturer recommend for spring pressure. They know the cam material and what it will take.