Profiler 176XC230491 - Cylinder Head Cast Aluminum Chevy Small Block 235cc 68cc 23Degree 2.125" x 1.600" Angle Plug, CNC Ported, Assembly w/ 1.550" springs for solid roller liftersProfiler 176XC230491 Cylinder Head Cast Aluminum Chevy Small Block 235cc 68cc 23Degree 2. 125" x 1. 600" Angle Plug, CNC Ported, Assembly w 1. 550" springs for solid roller lifters, Titanium Retainers The Pro Filer All American CNC ported SBC cylinder head has the same outstanding features as our "As Cast" SBC heads. But we have raised the performance level with a fully CNC ported 235cc intake runners and CNC'd combustion chamber. This has allowed us