Andy from Inland has asnwered this question a bunch of times and said it may weaken the door frame. I don't speak for Andy, and it's his original thought not mine. That makes sense to me. I'm not sure how it applies to an 86. As an alternative I put on a locking keyed hasp. Has a finished look and does not require any intrusive cutting etc. Stanley makes one. Low cost too.
Sail on silver girl. Sail on by. Your time has come to shine.
I installed one in my '59. Vintage Trailer Supply sells the deadbolt with the thinner bolt, I think it is about 5/8" thick.
You need to plan the installation carefully, so the bolt only goes through the web of the frame channel. If you cut through the flange of the frame channel it will be weaker. You can't use a standard deadbolt, the bolt is way too thick.