At about .6 lift spring maintenance become issue. Are you talking mechanical roller? Otherwise I wouldn't even think about a flat tappet with the spring pressures it takes to keep the valve train in check with lifts above .575 anyways.
To be sure,, your talking a solid street roller cam
Next question is, just how much street driving is 'STREET' to 'YOU'. Street can mean very different things to different people.
The diameter of the spring pocket (or available room for spring pockets) will dictate how large of a spring you can run. The larger the diameter the more 'spring' you get with out having to use a large stiff wire for the spring.
I guess the easy way is to say this... the small diameter spring has to work harder to keep the valve train in check,, work is HEAT, and HEAT causes springs to fail, loose tension, and eventually break. So .6 lift is much easier on a 1.55" springs than .6 on a 1.25" spring. Besides heat, what really beats up on springs is the RPM, the weight of the lifter, valve weight, even the rocker weight. You can invest in super light-weight components and use less spring,, and get longer life. Make sense?
I'm putting together a 10:1 street 383 for the truck right now and has a Howards hydraulic roller cam with .58 lift. I'm using a 1.55" Comp spring with 410psi on the nose, 200 on the seat. With 1.55:1 Crower shaft rockers and the heavy-ass hydraulic rollers I hope to keep things riding the lobe up to around 6200. We took the oil restrictors out of the block and used a large diameter pushrod in hopes to keep PLENTY of oil bathing and cooling the springs. Oil is the ONLY cooling the springs see. Some guys go to extremes with pressurized spring oilers trying to keep springs alive.
Thing is this new motor is going to be STREET with track as a novelty,, unlike the last configuration that was a track hero,, and STREET was simply a novelty with 13:1 compression and $11 a gallon VP fuel. It had .648 lift, would spin to 7600, made 666HP and was a expensive proposition to drive to the Sonic for cruise night,, but i COULD!
So I ask again,, what does 'STREET' mean to you???
exactly. i know it can be a tough question but i was mainly thinking of the "norm", .525-whatever maybe .650? just thinking and i realize the component materials and that sorts. i am not going to use titanium this or that, just the "normal" parts....my problem is I'm a "RPM" guy so my valve train needs to be stout. truth be told, i need the solid, oversize rods, shaft rockers, the BEST springs, titanium valves, etc......the poos a bitch when you try and "save".....