If you have both transom shields why can't you just compare them? Take some measurements?
They will both have part numbers cast onto them .
First thing, the gear ratio is different.
What drive is on the AD41B now?
What do you mean by 290 sp ? That it's a 290 single prop? The
Feedback from the machine shop was that the Mallory distributor was reliable, but had a limited advance curve compared to a modern version. That's why
So I dug into 2 different lower end gear cases. One is aBF100 (10hp) and the other a BF75Z (7.5 hp).
Inside the 10HP case I found the symbols square