The plans for the Wittman Tailwind came with plans for the Lycoming and the
Continental engines, I just looked at the plans and there is no dimension
for the width of the forward rails for the Continental engine.  I made mine
14 inches apart to fit the plate between the block and the pan, as per
Tracys pictures in his engine manual.  There was ample room for the pan.
The exhaust will be changed next winter when I have more time to work one
out with Jerry Hey, but for the present I have been working on the project
nine years now, so I would like to fly the plane this spring and refine some
things later.  JohnD