L99 and LS3 stock exhaust manifolds are the same?
 

I'm 99% sure but I need to know if the stock exhaust manifolds are the same. I know the catted extension isn't exactly the same.

The L99 catted mid-pipe will work on an LS3 but the LS3 will not fit very well on an L99 but is doable.

IIRC, the only difference is the L99 midpipe has a flexible section, whereas the LS3 pipe does not. Otherwise I think they are the same geometrically.

Yeah that's what I remember reading. I can use the flexible L99 pipes on an LS3 but not easily the other way around.

Manifolds should be identical.

The manifolds are the same.

my pipe wasnt flexable on my L99

Really? 1st I've heard of that. All the L99 cats should have a flexable part.

I had a flexible joint between my manifold and cats when I took them off to install headers.

if i can dig them out of my parts collection I will take a picture. There has been wierder on my car so it would not surprise me

Why are you asking???? Do you need a set? I have my stock ones, manifolds and cats, looking to sell. PM me if you are interested.