One of the best manifolds available for the B-series engines and in fact based on the TODA 4-2-1 manifolds: Tegiwa Stainless Steel Manifold 4-2-1 2.5 '' (B-series engines)
The finish of this manifold is very high. Partly Robot welded, high gloss polished, perfect fit portmatched and with excellent results!
The manifold has been tested on an almost standard Integra DC2 spec98 (based on a JDM 4-1 manifold, 2.5 '' catback and without RE-tune) and it already delivered 7.2 hp extra.
Compared to, for example, an almost standard b16a2, with a good re-tune, this should easily reach 15-17 hp.
(depending also on other modifications, where the results may also be different)
this header is manufactured for B series engines after 1992, with 1 probe hole. If you drive a B serie engine before 1992, you may have some modifications to do to put the 2nd sonde.