Large Bore CID LS3 (4.125") SPRING KIT:PAC 1209X 65 Int 136 194 243

65 Int 136 194 243 278 300 311 Exh 102 136 162 187 193 201

6 Int 145 205 255 290 305 Exh 110 143 185 202 225

Intake Port:        273cc                    Exhaust Port:     100cc

65 Int 145 205 251 291 318 320 Exh 111 153 193 209 219 221

Large Bore CID LS3 (4.125") SPRING KIT:PAC 1209X 65 Int 136 194 243Our CID LS3 4. 125 Bore heads include: Our in house CNC port PCD surfaced Proprietary competition valve job Hand blended valve job TSP 660 Spring Kit REV 2. 2 Intake Valve REV 1. 6 Exhaust Valve ***This is our most common setup, but if this doesnt meet your needs please call us so we can get you set up to your needs***