http://honda-tech.com/all-motor-natural ... tio-717928
PR3 head/B16 Block
STD = 11.643438609136867
.25 OS = 11.703231023151065
PR3 head/B17 Block
STD = 12.193487116069006
.25 OS = 12.256369577319077
PR3 head/B18C Block
STD = 12.58636786521145
.25 OS = 12.649248792586258
P72 head/B18C Block
STD = 12.924594026551906
.25 OS = 12.989047869209281
PR3 head/B18A/B Block
STD = 12.825536009218106
.25 OS = 12.88971493738735
P72 head/B18A/B Block
STD = 13.170743903246784
.25 OS = 13.236528215133324
All calculated using OEM 3 layer gasket @ .026 and the compression height provided by Omniman