Dual valve springs stock on 2.02 915 J Heads?

I haven't purchased the springs, retainers or locks yet. I am 95% certain of the cam I think will work well in the 390 at 7000ft and 10.5 compression/3.55 and as you know an np435 4 sp. I am still accumulating parts. I don't want to have to buy and re-buy, so taking my time on decisions.

I just don't think if I go thru the trouble of building this motor I will stay under .500 lift. It won't be much over, but the Howards Cam with the footnote(15) and the High lift Comp all seem to want to be over .500 for a SBM.