Question about quench

I am not against useing a cosmetic gasket. But I don't know if my engine deck surface is smooth enough for one. Ok Dumb question how do you measure deck Finish? The RA number.
Cometic told me last year that after more testing, they are now saying that Ra50 is an acceptable finish. My heads measured 40
And my block deck measured 60. The deck was not the best but I let it go. I used hylomar sealer around all the water and oil passages.
Time will tell if it works lol.