whats up guys i was wondering if a cracked header can cause a fluctuation in boost??? it usually happens from 3500-5000 rpm. its set at 15 now and it will drop and rise from 15 to ~11-12 PSI. the header on my car is most likely cracked all the way around from what i can see. if not could it be vavle springs??? motor has 100K on it and its a 87 GN. thanks for any help.