I would like to put some roller rockers on my car i was wondering which would be better 1.6 or 1.5 ratios. Motor is stock specs all forged pistons rods and crank nitrous is on the way other than that no other major install that would affect the motor when it comes to the valvetrain. any suggestions.

 

You're building an engine but not working the top end? You realize that that is where all the power is right?

1.6 rockers are a good way to pick up a little extra lift with virtually no penalty (except $$$!).

 

When you add roller rockers at a ratio that causes more lift, you will need to get new valvesprings that are designed for this higher lift. Like Josh said, 1.6RR are the most common ratio you'll see around this board. Some are running 1.7 with good results, but it's really up to you.

Check out Comp Cams 1.6 ratio Pro Magnums or Crane Gold 1.6RR

 

when i had to rebuild the motor i knew that i would probably ru nitrous so thats why i ran the all forged but other than that the motor is stock i didnt have the money to pour into the heads so i just left them stock but thanks for the advice is there a certain type of rr you have to have for the lt1 or are they all pretty much the same i know you have to run the narrow body.

 

If you're keeping the stock valvetrain, go with self-aligning roller rockers. I think Crane and Comp both make a self-aligning version. If you had guideplates and hardened pushrods, you wouldn't need the self-aligning version.