i want to change my valve springs to some 918 patriot springs but will i need a retune???? the truck will stay the same no more boost or n e thing just want to swap out the springs? this is off topic but i got my i/c and it doesnt say which way is in or out does it matter what way it goes or is their a specific inlet?

 

not unless you valves were floating before. if so you would be gaining boost where the valve float lost it. but other than that theres no reason why.