1.5 vs 1.6 rockers

If you make to move from 1.5 to 1.6 ratio.
Do you need to worry about the valve to piston clearance?

Worry? Yes. Why? You never know how much clearance you have let from the change even if you write down what clearances you had when you put it together the first time. CHECK! A small price to pay to avoid a high dollar screw up.

The 1.6 change will tame a "lopey" cam duration at idle for sure.
I don’t know how that is possible when it will intensify the cam. Not mello it out.

More importantly, increased RPM ramp speed and a bit more topend power. On My "B" block street set up.
IMO.
And there’s the proof.....