GM 462
Valve Exhaust Exhaust Open
Intake Lift w/ pipe
0.050 18 27 27
0.100 50 54 54
0.200 119 88 91
0.300 167 116 121
0.400 198 128 134
0.500 212 134 139
0.600 218 137 142
E/I 64% 67%
GM 462 IRON
Port: 156 cc
Chamber: 62 cc
Valve Sizes: 1.94/1.50
I Flow @ 0.400: 198 cfm

The 462 is one of the small-chamber heads used on 327s. The higher-horsepower applications used larger valves, but the ports were the same. The 462 head is representative of the small-chamber, 64cc heads. These heads are becoming very hard to find since they were discontinued at the end of 1968. If these heads are used on engines of 350 ci or larger, dished pistons are often required since the small chamber raises the compression. Pocket porting and larger valves can be added to make these heads work well, but the investment of money and time may not be the best use of your resources, especially when you consider that the World Products S/R Torquer heads are not only brand-new castings but are inexpensive and flow better.