Cross

iTrader: (10)

Alright guys I am trying to solve a never ending mystery it seems like... turn one corner and there always seems to be something else.

I ordered new LS3 Rockers and Pedestals for my 408 build with LS3 heads. I ordered them from the dealer.

It has been told to me that what I have now are not LS3 Rockers but LS7 Rockers. I need to know how to confirm one or the other as well as confirm if they require different pedestals.

Mind lending me some help here? I am looking for my recite now, but at this point I am a little confused. I ran across one thread that did say they were different.
However it also sounded like the pedestals would be different too. Some help here would be great.

Thanks

Upon a quick search I found a summit listing and want to confirm the part numbers:
LS3 Style Intake Rockers: 12569167
LS7 Style Intake Rockers: 12579617

TurboAv

iTrader: (6)

Cathedral port heads - LS1/LQ4/LQ9/LS1/LQ4/LQ9/LS6/LS2
Intake and Exhaust rockers are all the same – p/n 10214664
1.7:1 rocker ratio

Wide Rectangular – LS7
Intake and exhaust are different
Unique rockers to the LS7 head – will not work on any other head
1.8:1 rocker ratio
Intake rocker p/n 12579615 has offset
Exhaust rocker p/n 12579617

Tall Narrow Rectangular – L92/L76/LS3
Intake and exhaust rockers are different
1.7:1 rocker ratio
Intake rocker p/n 12569167 – has offset
Exhaust rocker p/n 10214664 – no offset, same as cathedral port heads

ls1itldo

iTrader: (30)

They are different

LS7 Rockers have a slightly different offset then the ls3 rockers on the intake as well as sit at a different angle to accommodate the ls7 head

the exhaust rockers are different as well as far as the angle goes, but there is no offset

LS3 use a pedestal for the Rockers. The LS7 Rockers do not require a pedestal as the it built into the head.

Im sure if you do a search you will find other differences, but that is all i can think of off the top of my head

Cross

iTrader: (10)

Ok guys then here is my next question. (Thank you very much for answering the first one)

If I ordered LS3 Rockers and LS3 Pedestals and I got LS7 Rockers and LS3 Pedestals because LS7 Pedestals don't exist... would the LS7 Rockers have even fit in the LS3 Pedestals and look like they were correct?

DietCoke

iTrader: (18)

YEs they'll physically bolt in, but they wont work.

Cross

iTrader: (10)

.... Would that be obvious?

Define what wouldn't work basically.

If the difference would be obvious or would have been found the minute the motor was started is what I am looking for.

If someone who did not know there was a difference and did not set out to get LS7 Rockers at what point would they know there was an issue, would it be when they tried to install them and obvious or would it look right but then fail for another reason?

Thanks again for the help

DietCoke

iTrader: (18)

the tips wont be centered over the valve, as the rockers are slightly physically different size and geometry. they will quickly destroy themselves and the valve tips as the LS7 is about 1/4" longer then the LS3 rocker from bolt hole to tip.

Cross

iTrader: (10)

To be clear the rockers would get destroyed. Alright now I have another thing to check into thank you for the answers Diet Coke and TurboAv and ls1itldo

DietCoke

iTrader: (18)

Yes, the rockers and the valve tips will both get destroyed.

Unreal

If you read his PRC head post it appears the rockers were hitting the spring retainers. That should have been noticed when the motor was turned over a few times.

Plus the ls7 rockers are 1.8 ratio so your .620 intake cam lift would now be .656".

Cross

iTrader: (10)

Exactly not after 500 miles. Something seems off but again if its the Rockers then I will make that very clear in the opening post but for the time being that is unclear.

I do think it would have caused coil bind too considering the lift.

Either way I am taking the time to research it and either prove they are or are not just as I did the push rod lengths.