[MrForbes]

You might be able to get a flathead bolt to replace the original, and countersink the hole in the transmission, to get it to fit. then it should clear the servo easily?

Although I don't know exactly where your chain is running, so it's hard to offer good advice.

How about you use a Paint program to draw your chain location on this drawing, then post the modified drawing. Then we can see exactly what your problem is?