Yes there are many ratios available for both small and big block as Ben Stated.

There are even 1.9 ratio Rocker Arms for big and some even for small block.

By using a larger ratio rocker arm you can create more lift on the valve with a smaller lobed cam. A word of caution anytime you do this you need to be aware of valve to piston clearance, valve spring coil bind and valve guide clearance. Most stock heads will only allow for a .500 lift max before you need to do head modifications. You can even stagger your ratios on the exhaust and intake sides depending on the type of engine combination you are putting together.

A good example is a story I was working on at Chevy High magazne. The engine they wanted to use was mish mosh of parts. 414 CID running 14:1 comp with AFR 210 eads running that he wanted to make 600 hp with. But based on track times he was no where near that. Once he stared telling me about his cam and valve train I could see why. he was running a small cam and was trying to get more flow using 1.65 ratio arms on the exhaust and 1.5 on the intake. His carb was also an 850 cfm carb. The owner was trying to band aid or fix a power problem by using different rocker arms rather then doing it the right way.

So basically we had to start over and redo the whole top end with new springs, locks, retainers, rocker arms, pushrods and especially the cam. They failed to cover what all was wrong with the engine combination in the story only the fact that they did, this and this, to get this result.

When the story ran with the new valve train, Dominator carb and edelbrock intake, he made made 620 HP running a 6.62 in the 1/8th. Computing out thats a 10.39 in the quarter. As you can image the cam was a big cam, but this was race type engine not a street piece so it mades its best power from 5k to 7K.

That story is in the Dec 04 issue of Chevy high

Anybody out there with an unanswered question? I'm set!
Far as I'm concerned, we can shut this thread down.

Have a good weekend, all.

JR

Thought I'd just through out a little info. I used a set of factory GM fast burn heads on my vette did a little port& polish work, match ported with crane rollers and man did this ever make a difference at a very low budget. The heads cost about $500.00 the rockers another $300.00. Hope this helps.

gellisvette said: The heads cost about $500.00 the rockers another $300.00. Hope this helps.

That's pretty darn reasonable.....Thanks!

JR

Something to be aware of is that on some motors, the 1.6 rockers will make the pushrods rub in the head guide slots.
I have a 78 L82 and would like to hear from anyone who has tried this on this engine!
Steve

Steve said: Something to be aware of is that on some motors, the 1.6 rockers will make the pushrods rub in the head guide slots. I have a 78 L82 and would like to hear from anyone who has tried this on this engine! Steve

I have not run them on a 78 L82 but I ran 1.6's on a 69 L-46 (350/350) but when I redid the heads I changed them from press in studs to screw in studs with pushrod guide plates. It has been my experience that the head guide slots wear out pretty easily. I cant think of any reason why 1.6 ratio rockers would wear when 1.5 didnt unless the angle changes enough for the inside facing of the guide slot to rub.

You can always "mock up" a 1.6 roller rocker and pushrod in the engine. Then slowly turn the engine over by hand and see how much clearance you have.
I have the Vortec heads which are a little different than yours, and I had to open up the pushrod holes quite a bit.
And thoughly inspect all your parts before installing them. I found a cracked (brand new) roller rocker out of the box. Must have cracked when they were pressing the trunnion bearing in. The parts guys and manufacturer coundn't believe.
Sarge

First time I got on in two days.

The mounting studs are the key to clearance and wear on the rocker. But the push rod length is also important. You need to watch where the open slot in the rocker moves in relation to the stud. If the end of the slot hits the stud, you will end up snapping the stud, or breaking the rocker, or bending push rods.

Some rockers require different length pushrods to keep the geometery in correct relation.

AfterSharks summary is right on the money. But I would just like to add that some times people use too much lift the do them anygood. Extra valve travel does open the valves longer and further, allowing better breathing. But if the rest of the intake is not up to the job, the extra opening won't help the engine breathe any better due to the other restrictions. Once again, it's a package deal. And watch the piston clearance.