Well If i had a perfectly good running car and was reaching 5200-5400 rpm without it breaking up or nosing over and still pulling good then no I wouldn't change springs If I was racing or trying to get every inch of performance out of it then yes maybe, there is just to many unknowns.don't know what the health of the internals are or mileage timing chain replaced ? compression good unless the OP is having some noticeable problems I don't know how much he has to gain by putting springs to increase pressure on a used cam and lifters.Plus getting the correct spring height on each spring and having the springs checked out to verify correct spring pressure for desirable results. don't know if heads are on car or off. that's why my reply was made as it was,.little more to it then throwing a set of springs out of a box on it and go.
