Hello, well i need some advice about the sound of my engine,...sounds really loud like marvels. I just rebuilt the engine with copper head gasket, arp bolts, low comprs' 8:1 wiseco piston and eagle rods, bore the cylinders to 0.20" over i took the piston to the machine shop so they can make better measure, also i check for pistons - cilynder clearances, rings gaps. I install a camshaft Crane12 both intake and exhaust are biger lobes than stock camshaft, so this may be what is make noise? My valve spring are weak? if they are weak why i have steady vacuum at 20psi? i think if my spring are weak my vacuum should be bouncing up and down..or the valve springs are jumping?..i need to replace the springs? or is the lifters than need more oil? i dont drive the car yet, i'm trying to find a problem with code 11. please any help and thank u for u'r time.