While not stated, I will assume that your heads are “period correct” for a 283:

The stock GM SBC valve spring from the mid 50’s to mid 60’ was installed at 1.70" and had a physical limit of about .490". Hot rodders routinely modified the installed height upwards to 1.75" so the spring would take more lift, but there as typically not enough pressure for high rpm.

A factory “stock” (single) spring in good condition is good for 5,000 or so rpm with a cam that has slow opening and closing ramps, i.e., the “stock” factory cam. This is where the engineering for cam geometry was performed and while it’s one of the fist places we want to modify, it’s the place most susceptible to failure because more lift and faster profile cams are beyond what the components were designed for. A lot of the “performance cams” have steeper opening and closing ramps and cam lobe lift acceleration rates thus they require a spring with greater seat and open pressure than a factory "stock” spring provides. The stock spring will not be able to control the valve at high rpm, causing float and bounce. These conditions, if occurring even rarely, are very bad for the valve train and almost always lead to broken parts.

Your cam specs seem reasonable for a mild performance, “streetable” engine and you’ll have a noticeable “lopy” idle. Perhaps Tech (an others) will add more precise data for you if asked.

Have Fun!
Glenn