omegac1

I am installing LG headers right now so I have my 2003 apart. I was wondering since the hood is popped, if it would be benefical to change my stock rockers to Yella Tera Ultra lights 1.7 ratio? Do I have to change anything else in the valve train like springs or push rods to use these? How much HP would I gain over stock rockers? Other mods are: Blackwing intake, 85mm TB, LG long tubes with high flow cats, Borla stinger catback, and LS6 intake.

lucky131969

Pretty much no gain(at least that you will feel or notice). Unless you are changing the cam, I'd leave the rockers alone.

Hopefully the LS6 intake you list is the "air intake", and not intake manifold........

81c3

Waste of money if you dont plan on upgrading the cam. A nice insurance policy is to have the stock rockers re fitted with a set of Comp Cams trunnions and caged needle bearings for $200. Hinson Supercars did mine and Im happy I can sleep better at night.

DeltaBravo

Did you replace pushrods too, or is it unnecessary?

Dennis

ctusser

Don't need to replace pushrods unless going to heavier than stock springs.

DeltaBravo

Thanks!

Dennis

vettenuts

Maybe. These are not just "bolt them in and go". You need to verify the geometry and any shimming required to narrow the wipe pattern on the valve stem will also change the pushrod requirements. Also, not sure how much more inertia they have over stock but I have never seen them installed with stock springs. Since the stock springs are marginal and depending on mileage could be on the edge, the rockers may be just enough to float the valve train early. I am running the rockers on my setup, but you can't just bolt them in and forget about it.

81c3

Im not sure were on the same page here. The rockers are the exact ones that came off the engine in the first place. Each one is marked and put right back in it original position. Theres no geometry issues or shimming or anything else here to worry about.

Y2Kvert4me

vettenuts' post was spot on for the comment he quoted, and the OP question concerning the YT roller rocker arms. Pushrod length may have to change if the new rockers need shimming to set correct geometry, which they very commonly do.

Ikester

I have a cam and im still using stock rockers

81c3

All true statements. But to answer Delta Bravos question, no, you dont need to change pushrods when upgrading the trunnions only on stock rockers. I upgraded my springs, pushrods and rockers as well as my cam being .595/.598 It all works together.

vettenuts

I was referring to the original question with regards to installing YT's and the need for springs and/or pushrods. I have re-read the thread and I guess my reply was somewhat confusing as to what I was referring to.