Did you mean LS6 heads and cam? Because the LS1 has a 3.9" bore and the LS2 has a 4" bore.adearmas said:Talk to your GM dealer. Some GM dealers will be able to put on LS2 heads and cams, flowmeter and some thermostat changes (depending on your climate), and a drop in KN filter to add close to 30 hp under warranty. To that you may also request a better exhaust system from GM like SLP and still be under warranty. Probably you could get close to 390 hp. Some GM dealers may not.