On an average... how much pressure is too much seat and open pressure for a mild hyd flat tappet street cam? Say basically a 340 cam or a touch warmer cam. Slightly higher ramp speed but basically a 340 cam? Just curious what a 5,800 rpm street engine spring pressure should be? I don’t see a need to wipe a cam but also don’t want to float the valves at 5,300 either. Thanks guys.

360/ X heads
9:1 compression
HP manifolds.

I would always go by the cam manufacturers spring recommendations. No way to know requirements based on sound of cam or looking at lobes. My 2💰

What type(stock or anti pump up) and brand of lifters are you going to use and what type of rocker gear and pushrods?

A simple approach would be use the spring specs for the .474 or .484 purple shaft cam. There's a million of those in small blocks over the last 30+ years.

I've measured stock red valve springs for small blocks around 90 pounds at installed height. IIRC typical spring pressures for flat tappet hydraulic lifters for street use are around 110 on the seat, no more than 350 open, to keep from wiping out the internals of the lifter. To get the most RPM I think it's important to get as much pre-load out of the lifters as possible so that they are not pumping up at higher rpm's and keeping the valves open - in other words - adjustable rockers or shims.

Pick a cam/lifter/rocker combo.......then decide on the appropriate springs.