NEW GM 317 Cores
2.02"/1.575" Stainless Steel Valves
TSP .660" Lift Dual Valve Spring Kit w/ PAC Valve Springs Complete with Retainers, Seats, & Seals
Completely Assembled and Milled to your Specifications
65-72cc Chambers

All PRC cylinder heads are extensively researched and tested. The flow data below shows the superior performance of the PRC stage 2.5 6.0L cylinder heads!
3.910" Flow Plate - No Exhaust Pipe

Lift Intake Flow Exhaust Flow
.200" 147 cfm 114 cfm
.300" 209 cfm 152 cfm
.400" 258 cfm 191 cfm
.500" 294 cfm 207 cfm
.600 316 cfm 226 cfm