1982 Spectre centre bolt on bottom - where does it go into?

Hi all!
Going to do a mock-up assembly of my used spectre exhaust manifold, to fit it to a GT750 - same downpipes, same engine case.
On the picture, You see the large hole on the bracket on the cross-over pipe. Where does this bolt end up?
Are there also any washers and dampeners I have to look for?
Manifolds are being cleaned to bare metal - inside and outside, any dents repaired, and coated in ceramic black gloss finish. Quite a job! 

Thanks in advance!
ErlingW in Oslo, Norway

A threaded hole on the oil pan.

Thank You! 
Then, I'll just put the lower case and oil pan into the frame, to figure out how to adapt this to my bike.

ErlingW

Here is a very crappy diagram showing all the bits and bobs connected to the Spectre exhaust system.

www.partzilla.com/catalog/kawasaki/motor...re-kz750-n1/mufflers

Here is a much more gooder diagram of the GT system for comparison.

images.cmsnl.com/img/partslists/kawasaki...ae0369e1140_1690.gif