i just recently put in a 75 mm mass air with 24 pound injectors on my 5.0 and since than ive had a problem with it studdaring and it pings a lil but not all the time, it will run great for a while and run like **** out of no where, i have alot of crankcase pressure could this be my problem or should i keep looing

i also have cobra upper and lower a crane came and 70mm throttle body for more air can someone help me?