Higher strength springs place a heavier burden on the timing chain. If you have high miles and you put stronger springs in, you may want to invest in a new timing chain as a precaution. Not saying you have to, just saying its something to think about.

i gotcha. its probably a good thing to replace anyways.

ok, but getting the springs anyways are a good precaution...say i get those rockers then some new pushrods. then do i need those springs or can i get away with it?

It really is hard to say. Some people have done it with no problems. However due to the added stress if you have a weak spring or worn out springs damage could result (spring snap, valve contacts a piston, boom). The safest bet is to do stronger springs, retainers, and rods. How safe do you want to feel? If you get an aftermarket pcm you will probably experiance valve float without the strong springs and OR rods due to the higher rpm range.

Any time you start modding there is always supporting mods that should be done. I did the 1.9 rockers and was fine (low miles 30K) until I did the PCM. I started to get valve float at about 5800 rpm. I was going to get a cam anyway so I upgraded my springs, retainers, rods and the valve float went away. Now with the cam I did the timing chain at the same time. I probably would have been fine without it, but with all the valvetrain upgrades my car can safely shift up to 7 grand. How much is peace of mind worth?

Peace of mind is worth a lot, but to buy that piece is in short supply Does a afttermarket PCM fix the timing without adding a new chain?

No, in fact a PCM will raise the max timing from 15 to above 18. If conditions are right and your not getting any KR a PCM could put more stress on it. If you not racing every weekend and not getting on it at every stop light you will probably be all right without changing the timing chain.