i did bought an fd manifold and i'm going to do the swap soon to my 91 13bt engine...i wonder if anyone done this before.i thing yes,and how exactly did it?any pic?any help welcome....

 

cut the the surrounding excess around the third gen manifold...order the adapter plate flange from mazdatrix, and weld that one on to your lower third gen manifold making sure the mounting holes clear to bolt it up to the block...

Easier said then done...but it's still pretty easy.....i just kept it short and sweet and to the point...lol

 

it takes too much time and effort. here's my modified TII intake to an old school 13-B

 

The FD manifold intake runners enter the engine at a downward angle. The FC runners do not. If you were to literally just bolt on an adapter for the bolt patterns, your runner transition would be absolutely terrible. The best way to do it is to not use the FD lower at all. Retain the FC lower and adapt the FD upper to fit it. This is easier and doesn't suffer as many drawbacks as trying to use the entire FD manifold.