[HeavyChevy]

I heard that i could add some 1.6 ratio rocker arms to my 350ci 91 chevy caprice engine and gain anywhere from 15 to 30 horse power is this true, and also could i use the stock rocker spring and valve cover or what type would i need to do to make this work properly.

 

[MrBuick (Magnum)]

On the LT1, the valvespring is more important, than the 1.6 rocker. The valve springs on the LT1 cause valve float starting around 4500 RPM. I'm whiling to bet the L05/L03 valve springs are not any better. Going to a higher ratio rocker, increases your valve lift a decent amount, and also increases the duration slightly. I know on the LT1, you have to flatten out the bottom of the L on the braces inside the valve cover to clear the wide body Comp Pro Magnum rockers. I think the valve covers are very close to being the same.

As for gaining 15-30hp? I'd say that is very optemistic, but it will bump things up a bit. The cam in the non-police, car L05 is rather pathetic. Worth doing? L05's will never be a power house with those swirl port heads, and intake manifold that chokes the life out of it.

 

[ekm1190]

As for gaining 15-30hp? I'd say that is very optemistic, but it will bump things up a bit.

I've agree its pretty optimistic, i've heard more around 5-7 hp gains. At that point I would only upgrade them if you're planning on rebuilding the whole motor, because that's when it'll really start to add up. Otherwise i'd leave it alone for now, but that's my opinion.

 

[Dwayne J]

The TBI motors are so low rpm you might actually get away with stock springs. That HP gain is pure pipe dream though. I doubt you would even see that with rockers and tuning. Now with headers, rockers and tuning I could see it.