Hi,

I'm thinking of upgrading to 1.6 ratio rocker arms in my LT1.

From your experience, would this have the same effect as replacing the cam, as far as:
- increased engine power,
- idle quality (i.e. rough idle), and
- reduced engine vacuum (i.e. for braking)?

Thanks,
Rob

 

As long as you put the appropriate valve spring in place.

- you should gain power, most likely in the mid to upper rpm range. Also this will be determined by other supporting mods, intake, exhaust, tuning ect ect.

- Idle quality should not change at all, or at least bearly noticeable. The duration and Lobe sep remain the same.

- Should have no change in vaccume assisted components.

 

I second his opinion. You will notice an increase in exhaust volume by the tone of it. Just be sure to replace the springs if they are near the end of their life...

 

...A rocker arm switch (reguardless of the ratio you go up to) is more of a "subtle" difference when compared to a well chosen cam swap......you "could" gain Aproximately 10 to 15 HP with the rockers....which is pretty hard to even feel reguardless of what people will tell you......Im not saying it's not worth it, because it is, especially when the day comes that you have other supporting engine mods, but the gains are very small from rocker arms alone "especially" with an otherwise stock LT1.......your idle won't change much at all either..........and having reduced engine vacuum won't occur to any degree either........Something that "many" people don't realise is that a rocker ratio change "not only" changes cam lift, but cam "duration" as well..........rule of thumb is : every half-point of rocker arm added, will yeild 1 degree of cam duration @ 50thou tapped lift.......example: a cam with 224@50 duration with 1.5 rockers, will be right at 226@ 50 duration with 1.6 rockers...........

 

There is no downside to swapping to 1.6 rockers. A bit more mid and top end hp. Use quality rockers like pro mags and LT4 springs and you'll be happy.

 

Its a lot of work with little gains on a stock motor. LT4 valvesprings barely handle the LT4 hotcam so you limit what cam you might waht to run in the future by going with that spring. Now if you want to kick it up later on when you have cash or free time but not right now then look at a spring that can handle a wide range of cams so you dont have to go through the same work twice. But right now all youll likely notice is the extra noise of the rockers.