Rigging Wire replaces Cotter Pin

[Stevienjackson]

Is it acceptable to use rigging wire in place of cotter pins? I'm replacing the port spreader and upper shroud on my Ranger 33. I discovered that rigging wire was used instead of a cotter pin to retain the inward facing clevis pin on the mast tang. On the opposite side there is a plastic washer under the tang which seems to increase the clearance between mast and tang. Should I add a similar washer to bring the port tang further out so I can install a proper pin? Clearances are very narrow, and the tangs are probably too short. But, installing longer tangs might result in making the current shrouds to long to use.

Also, any suggestions on where to find rig tension guidelines for a Ranger 33?

I'm a new member, and I'm really learning a lot from all the comments I've read.
Thanks,
Steve