Thank you Shaun for your reply greatly appreciated.
I cannot compare to the manifold i removed because the previous owner welded a steel pipe
on it and the weld failed.
There is a notch in the manifold and a tab in the pipe but the pipe has little loose
and there is an exhaust leak. It is a new after market manifold which have few defects
I think the dimentions are little different compared to the original.
I will try to find some heat resistant packing to put under the bell shaped part
of the pipe to stop leaks.
Thanks again !!!