it is in your best interest to contact a cam comp like compcams to help decide was is best for your l31. they have a few cams that can give you a bump up that wont throw off the pcm real bad. the catch is they are not listed as for the vortec 350's so they will need to match something for you with more parts likely added on. it likr;y add on lifters and maybe rocker as we;;. you can do rockers alone as well. i use their 1.52 self aligning ones and got a small bump. goes well with my intake and full exhaust setup.