My friend just bought a used header meant for a B18B Integra LS for his B16A2. This is just a temporary fix cuz his factory manifold is cracked. Question is, will the header fit? I know that if it does fit, it might hang a bit low considering the B18B has a taller deck height than the B16A2...will this be a problem? The engine is a 99 Civic Si.

 

yea all b series headers are interchangable

 

The Si's cat has a flange that is oriented at a different angle than that of the LS, so you will either need to modify the Si cat or use an LS or ITR cat.

 

Interchangable But..may need slight mods