it will bolt up the the GTIR manifold. Both share a T2 flange. It should clear the block fine. The oil/water lines from a T-25/28 should bolt up. I beleive there is a whole section in the back of a new SCC that has this in it. They put the GT28RS on a 240SR. Ill look it up for you tonight.
get a hold of FTF motorsports, he's fitted quite a few of them on several different applications with no "jerry-riggin" on the clearance issues, he knows how to do it all nice and proper!!! he can probably get you a great price on it(GT28RS) too!!
With the GTiR Manifold There are clearence issues with the block. Of course it depends on how you oreint the Comp outlet. On the G20 that I upgraded the comp points down so we had to shave a bit off the edge where the block swells to meet the bell houseing on the tranny. It also hit the front mount on the P11 which we had to shave as well. Of course on a B14/B13 youll have more clearence in the front motor mount area.
If you have any questions feel free to email me.