Any gains adding 1.6 rockers to stock 273?

273 Cleanup Port/Valve Job 1.78"/1.50"
(pretty much a "stock" class vavle job)
0.100" 49 43
0.200" 98 85
0.250" 124 100
0.300" 145 112
0.350" 162 120
0.400" 179 125
0.450" 188 129
0.500" 190 132
0.550" 185 134
0.600" 177 135
Depending how much clean up and valve job helped, which could be decent amount.
But let's say these are right so were talking .400-.450" range 179-188 cfm range. In a engine that's makes like 1 hp per cfm. Not saying there won't be a gain but highly doubt be much plus valve float could start earlier with 1.6.