My problem is that my new crate engine runs lean, especially in open loop mode. This engine is supposed to be the low output stock pre 86 350. I have the fpr turned up all the way, too. At idle the o2 output will be around .6 volts but when i tried to bring it up to around 2500 rms to break in the cam it droped to almost zero volts (0-.12 volts) and the ses light came on because of the lean condidtion. Could this solely be the injectors causing this? The ones in the lo5 350's are only rated at 10# more than the 305 ones so i dont see how having the 305 ones could cause such a huge difference. Could this be my fuel pump causing this because its supplying inadiquate pressure because its going bad? Maybe a bad map sensor? Some of you have probably seen my pissing and moaning about this and excessive heat probs. in other posts but i really need to get this car running. My parents are tired of having me sponge their cars all week so i can get to class and theyre really pushing me to rap this swap up.