proform 1.6 roller rockers? and build question

[badbird]

Im thinking of buying a set of proform 1.6 full roller rockers, But I have a few questions first.
Anyone ever had any proform rockers fail?
will my stock pushrods work?
Will the stock valve covers fit?
Do I need to replace the valve springs?
what lifters would be a good preformance replacement?
Im thinking I might pull my heads, and have them rebuilt.
Now my question is, If I pull the heads, gasket match the intake and heads, replace the lifters,pushrods,valve springs and put on the roller rockers.
Will the new top end, damage the 70K+ milage bottom?

Thanks.

[Z28pr0jekt]

I'll answer a couple of these that I know

will my stock pushrods work? Yes, but hardened/chromemoly pushrods are cheap insurance

Will the stock valve covers fit? Yes but they will probably need to be clearanced

Do I need to replace the valve springs? Yes, at least LT4 springs, but preferably something stronger for future mods

what lifters would be a good performance replacement? comp stock replacements or LS7s

Will the new top end, damage the 70K+ mileage bottom? no, unless you are revving too high and your bottom end is in bad condition to begin with