I have a whippled 5.3L, i'm about to put a zo6 cam ls6 spring and hardened pushrods. which if any roller rockers should i get and what ratio?

 

Go for any non adjustable rocker. IMO that is the only best route. Yes they may cost a bit more but there is a hell of alot less head ache with a non adjustable rocker!!!!! But, stock rockers are perfectly fine. If you are looking for more lift then just get a bigger cam. Otherwise stay at the stock 1.7 ratio.

Jesel, Yella Terra and Granatelli make a very nice non adjustable shaft mount rocker. Those are the best in my eyes and why I run Jesels and will run nothing else.

 

The stock rockers are pretty good and will be a little quieter than the roller tipped ones. I have the Yella Terra's 1.7 that I just removed from my 2001 LS1 motor after 14K miles because I wanted to quiet down the valve train just a little by putting the stock rockers back on (I have the comp 918 springs which also contribute to valvetrain noise). You should stick with the stock 1.7 ratio which will give you .550" lift with the z06 cam. I would also consider a better valve spring (like the Crane duals) to help close the intake valve against the boost pressure you'll be running....

 

My valvetrain is quieter than it was stock!!!!!!!!!!!!!!!

 

That could be the difference between Jesels and Yella Terra's (and comp 918 springs too). Cam ramp rates will also affect the valvetrain noise. The noise was noticeable only at certain rpms. I have about 1 turn of pre-load on the stock lifters for my C5 (where I had installed the Yella's). The valvetrain noise was cut in half by only re-installing the stock rockers. But of course, your mileage may vary...