Converting to shielded ignition

[Bill Morgan]

I am in the process of converting my Bendix S4LN-21 magnetos to shielded ignition.
I have found shielded ignition harnesses for sale that appear to have very large inserts
(4) that go into the distributor block. I have not ordered a set yet due to my concern
that it will not fit. Is there any requirements to make modification to my magneto
in order for the shielded harness to fit?

 

[bob turner]

 

[Blue Jay 3]

 

[1940_owner]