Z28Justin

I've heard that if you get roller rockers with a higher mileage motor that you need to buy new springs is that true? I have a 305 with 142,000. Also, I believe that I need self aligning, but I'm not positive.

Spectre

could be , makes sense you're applying a bit more pressure on the springs.

Stekman

Rockers don't apply the pressure to the springs. It's the other way around. (to be technically correct its force, not pressure). Consider this: either way, the closed height will be the same. But the 1.6 will open farther. This compresses the spring more. The more compressed the spring gets, the more force it exerts on the valve and the rocker.

The biggest issue is the lift. There is only about .460-.480" lift to play around with before you start messing with clearance issues. On a stock cam, go for it.

If you really do want to replace some springs, use the Comp 981 valve springs.

Z28Justin

I didn't think it would make a difference, but I thought I remember reading that somwhere. As long as I'm not going to experiance any valve float I'd rather not replace my springs.

Stekman

Stock springs are about as weak as can be. From the factory, they have about 80 or so lbs on the seat. From there, they can only get weaker. The lesser the amount of seat pressure, the lower the valve float RPM will be. That is one thing. Another fact is the fact that factory springs in themselves are total crap.

Z28Justin

well do you think it would be safe for me to use the stock springs, or do you think I should get new springs?

Stekman

What cam are you using? If stock, then i guess it wouldn't hurt. if any form of aftermarket, get new springs.

If it were me, I would get new springs no matter what.

Spectre

Ok .. compression is the word I should have used

Id change any parts removed.. been a high mileage motor.