1/4 -- 3/8
thats a upset offset,
Looks a bit like a brake bleeder wrench.
Mike
K D 291
deep off set break bleeding wrench
Your right Mike thanks
Agree with brake bleeder tool. On the Ford special tools board in the dealers shop, there were a number of extreme offset wrenches for accessing 6 cylinder manifold bolts, and early Ford-o-matics, some neat unusual tools.. also some of the distributor hold down wrenches had some wicked curves.