ls3 or l99

[rjs1le]

Kind of a dumb question, how to tell if you have an ls3 or l99?

[MrChrisLS3]

Your transmission...if it's a manual it's LS3, automatic is L99.

[14ssrs6man]

You have a 1LE, you have a LS3

[SSEssence]

auto = L99, manual = LS3

[frankwjr]

L99+VVT delete=LS3+auto...lulz

oh and the exhaust too...and the rear gear ratio...and the?...should be it...peace out...

[rjs1le]

Thanks guys

[CamaroFred]

Originally Posted by frankwjr

L99+VVT delete=LS3+auto...lulz

oh and the exhaust too...and the rear gear ratio...and the?...should be it...peace out...

Different block between the L99 and the LS3.
The L99 has extra oil passages for the AFM and is weaker because of that.

[rontammy0]

Originally Posted by CamaroFred

Different block between the L99 and the LS3.
The L99 has extra oil passages for the AFM and is weaker because of that.

I see this posted once in a while ....yet cant find one single example of people hard charging their l99.... going bolt on for bolt on with any ls3 and grenading because of it. Im not talking about could have or should have...Im looking for good examples of the weak l99.

[G701LE]

Originally Posted by frankwjr

L99+VVT delete=LS3+auto...lulz

oh and the exhaust too...and the rear gear ratio...and the?...should be it...peace out...

LS3 has better compression too....

[CamaroFred]

Originally Posted by rontammy0

I see this posted once in a while ....yet cant find one single example of people hard charging their l99.... going bolt on for bolt on with any ls3 and grenading because of it. Im not talking about could have or should have...Im looking for good examples of the weak l99.

Yeah, you have to be an engineering marvel to notice the differences.
It's not that it's going to grenade, when the flex is in the block tolerances change, your lifters don't lift like they should, pistons go to a different compression ratio, etc.

These days all that is accounted for before production begins. So different parts because of more change.

Not that the average driver will notice it in his ownership. The L99 is very well designed and should last a lifetime. That is what it is designed to do.

Well, even the LS3 has to deal with these issues, but the tolerances can be tighter because the flex is not as much.

imagine walking onto a bridge on concrete caissons. Sure it sways a bit, all bridges do, right? The higher, the longer, the more sway. All designed in. You will even feel movement on a simple overpass no longer than 20 feet. Not easily noticed if you are sitting in a car on top of springs.

Now walk on to something like the Golden Gate Bridge. Hanging by cables. It's like hold onto your head! Have you ever wondered what that feels like on top of the support towers?

Just to make a point about how everything has flex and has to be allowed for. The L99 will have more flex than the LS3. Simple as that.

[rontammy0]

Originally Posted by CamaroFred

Yeah, you have to be an engineering marvel to notice the differences.
It's not that it's going to grenade, when the flex is in the block tolerances change, your lifters don't lift like they should, pistons go to a different compression ratio, etc.

These days all that is accounted for before production begins. So different parts because of more change.

Not that the average driver will notice it in his ownership. The L99 is very well designed and should last a lifetime. That is what it is designed to do.

Well, even the LS3 has to deal with these issues, but the tolerances can be tighter because the flex is not as much.

imagine walking onto a bridge on concrete caissons. Sure it sways a bit, all bridges do, right? The higher, the longer, the more sway. All designed in. You will even feel movement on a simple overpass no longer than 20 feet. Not easily noticed if you are sitting in a car on top of springs.

Now walk on to something like the Golden Gate Bridge. Hanging by cables. It's like hold onto your head! Have you ever wondered what that feels like on top of the support towers?

Just to make a point about how everything has flex and has to be allowed for. The L99 will have more flex than the LS3. Simple as that.

Lol you lost me at engineering marvel haha. But i get it.

[Bo White]

Engine block 12623967
•Direct replacement for:
2009-2012 L9H
2010-2012 L94
2008-2013 LS3
2010-2013 L99
2007-2008 L92

[CFD]

Originally Posted by Bo White

Engine block 12623967
•Direct replacement for:
2009-2012 L9H
2010-2012 L94
2008-2013 LS3
2010-2013 L99
2007-2008 L92

Some think the blocks are different but as the part # shows they are the same block, no differences.