The '92 FC3 [2nd gen] and '93 FD3 [3rd gen] exhaust manifold bolt
 patterns look identical.
 Are they interchangeable when not used in an automotive application?

 Harry

 If you are referring to the exhaust bolt patterns on the rotor housings
 the answer is yes. The exhaust manifolds however are completely
 different
 of course. The rotor housings are interchangeable however there may
 be detail
 improvements to the 3rd gen rotor housings.

 Paul Lamar



Would you happen to know the measurements for the turbo bolt pattern for
the FC3 turbo exhaust manifold?

Harry

looking at the manifold bolted to the rotor housings the  bolts are
are 1004 mm apart, out side to out side, with a 10 mm bolt.
That makes it 94 mm center to center.

Top to bottom they are 65 mm apart out side to out side.
That is 55 mm center to center.

The flange is 82 mm high and 120 mm wide.

There are two oval ports 24 mm wide by 52mm high  10 mm apart
centered on the flange.

Paul Lamar