as i said stock internal b20 with gsr head made 258whp for 5 years daily driven on 8 psi with nothing more than arp rod bolt for added durability on the stock bigger and slightly heavier 84mm pistons. the ls boosted is very reliable. b20b4 will only go 8psi. when i tried 10 thats what cracked my sleeve.the b20 with b20 or ls head will make approx 220-240 give or take depending on a chipped and tuned ecu and the tunner. no tune with a b20 and boost is a bad combination. so if tunning is out of the question an ls will last longer with say a crappy fmu, but i went with ls and the tune. but b20 on 8psi will last and have a little more torque but no more than 8psi.