Roller Rockers 1.5 vs 1.6

33IMP said
About half way down the cylinder.
I check v to p clearance at least 15° on either side of TDC, for intake and exhaust....

Exactly. I thought we were talking about valve to piston clearance (or lack of) if the OP uses 1.6 rockers instead of the stock 1.5's. May be I missed something in the middle.