317 heads
#3
317 have D Exhaust port like ls6/243 heads and 72cc chamber
flow more than 241
241 have 66cc chamber, flow less than 317 O exhaust port
both use 2.00 intake and 1.55 exhaust valve
flow more than 241
241 have 66cc chamber, flow less than 317 O exhaust port
both use 2.00 intake and 1.55 exhaust valve