stock manifold size ?

[Derek81]

Does anybody know the size of the primaries on the stock l67 exhaust manifold? Also what size is the crossover pipe? Tried a search and couldn't come up with an answer.
Thanks

 

[BillBoost37]

Front will differ from rear manifold wise. And the front is the restriction.

 

[jteske88]

I was wondering the same thing? I got a zzp bolt in 3incher and I just don't think it will bolt in.

 

[Derek81]

Hmmm ok well I saw that the speed daddy headers advertise a 1.5 in primary and I was wondering how much bigger, if any, it is over stock. I'm aware that the design of the headers will outflow the stock even if they are the same size, just curious what the difference would be in size between the 2. I'm also pretty sure the the crossover is larger on the sd headers which would also improve flow. Just trying to get more info before making a move

 

[darkhorizon]

you cant really measure stock vs anything else.... Stock has a very specific upswept design that flows ALOT more than any non upswept exhaust part.

Headers are bigger, alot bigger, and they are well headers.... Also, supercharged cars should always have a giant exhaust system, the whole "low end torque loss" found in NA cars is irrelivant.