PRC CNC Porting Service - Cathedral Port Heads (Customer Supplied Castings)

The price listed is for you sending your cathedral port cylinder heads (4.8/5.3, LS1, LS6, LS2, LQ4/9) to us for porting. Our stage 1 porting service will include the re-use of the stock vales. Stage 2.5 will include aftermarket 2.02/1.57 stainless steel valves. We also offer valve spring upgrades. PRC CNC Porting/Machining Service Includes: Disassembly Deep Cleaning CNC Porting CNC Valve Job CNC Engraving of PRC Logos CNC Milling to Your Specs Reassembly Pressure Testing With all PRC cylinder heads, quality and performance are our two highest priorities! In addition to this, you will not find a better performing cylinder head porting service at this price. Call one of our sales consultants today if you have any questions or if you would like to discuss your specific application. ​ Stage 2.5 5.3L Flow Chart Lift Intake Flow Exhaust Flow .200" 147 cfm 111 cfm .300" 207 cfm 145 cfm .400" 254 cfm 185 cfm .500" 291 cfm 204 cfm .600" 308 cfm 223 cfm Stage 1.0 LS6 Flow Chart Lift Intake Flow Exhaust Flow .200" 147 cfm 114 cfm .300" 207 cfm 148 cfm .400" 255 cfm 187 cfm .500" 292 cfm 202 cfm .600" 313 cfm 220 cfm Stage 2.5 LS6 Flow Chart Lift Intake Flow Exhaust Flow .200" 147 cfm 114 cfm .300" 207 cfm 152 cfm .400" 255 cfm 191 cfm .500" 292 cfm 207 cfm .600" 316 cfm 226 cfm Stage 1.0 LQ9 Flow Chart Lift Intake Flow Exhaust Flow .200" 147 cfm 114 cfm .300" 207 cfm 148 cfm .400" 255 cfm 187 cfm .500" 292 cfm 202 cfm .600" 313 cfm 220 cfm Stage 2.5 LQ9 Flow Chart 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 ​ *Typically a 1-2 week turn around time once heads arrive at our facility. *Stage 1 porting NOT available for 4.8L and 5.3L castings due to the factory 1.94" intake valve size. All 4.8L and 5.3L cylinder heads must select the stage 2.5 option that includes 2.02"/1.57" stainless steel valves!