would a 1999 5.9 ISB Cummins Industrial exhaust mainfold 2pc. fit on a 12v? i know the 24v will and most likely the comon rail

 

i would think so no definite answers but from what i have been reading i dont see why not

 

YOU WOULD THINK THAT THEY WOULD BE THE SAME

 

As long as it is for a 12valve head it'll work.

 

im just getting a cr exhaust manifold and gunna use that

 

24v or CR exhaust manifold will not be a bolt up fit.

Well thats not entirely true either....
They will bolt right up as they have the same bolt pattern,BUT,the 24v and CR heads have round exhaust ports where the 12v exhaust ports are rectangular.You could make the CR or 24v manifolds work but you would have to do ALOT of porting work on them to flow properly.

 

If you port them that much they WILL crack.

 

why would you do that? you will have to redo your intake pipeing, exhaust pipeing, and most of the cr's run 2nd gen manifolds because they flow even and sound better.

 

so it will not fit?

 

It'll bolt on but it wont work right. You'd be better off with the stocker.