In this case, since the OP is using aftermarket heads that use a taller installed height than the factory heads, the recommended springs won’t be the best fit.
You’d have to look at the specs of the recommended springs, then find something with similar load specs that will be a better fit for the different installed height.
Stock heads have a nominal 1.650-1.700 installed height.
SB Mopar RPM heads have a nominal 1.800 installed height.
