I installed 1.9 Rockers only on my GTP years ago. At about 70,000 miles after the rockers were installed I broke an exhaust valve spring on number 2. I've NEVER shifted above 6k or over reved it in anyway. I used to race quite a bit so it was wound a few times to say the least. Since the car was a DD at the time I installed a new spring from the dealer. I was LUCKY and I cought it before anything major happened. The valve was on the verge of dropping and the spring was damn near completely collapsed. When I pressured up the cylinder to replace the spring the spring literally fell apart.

About 6 months later I replaced all the valve springs with CC 105# spring/retainers and while I was in there installed a set of PRJ Viton valve seals and Reusable rocker bolts. I have since added about 20,000 miles with this new setup and all is well.

I saved the old springs with the new spring I temporarily installed. I have yet to measure them, but on the workbench feeling the spring pressure and looking at the heights you can see and feel the difference very well. I'm betting the old springs are WAY undertolerence, but I can't prove that just yet. Once of these days i'm going to have them measured just for my knowledge. One of these days.

I recommend WHATEVER rocker arms you install replace your springs/retainers/and valve seals while you're in there. Don't skimp out on this parts, doing my springs/retainers/seals/RR bolts/VC gaskets only cost me $150, don't cheap out like I did originally. Do it right.

Keep in mind, I was one of those guys for years on ClubGP saying for years, "don't replace valve springs, its a waste of money blah blah blah" till I had it happen to me. Now I sing a different tune because I became one of those guys, one of the many and growing club who broke valve springs on 1.9 rockers.

The choice is yours but i'll say, if your doing it, don't be a cheap ass, spend the extra $150 and do it right the first time. Keep in mind, when it happens to you, you won't probably be as lucky as me and you'll drop a valve and loose your motor. Food for thought...