you would have to replace the timing chain at a minimum. if you do a valve spring stronger than 105's most people suggest a double roller timing chain and if you do the double roller you will need a machined oil pump cover and/or 2 timing cover gaskets because the chain is thicker. lot's of people just do a stock replacement timing chain with 105's and a S1X cam. and when you change the springs, you will need LS style beehive retainers, new locks and new seals.