16:1 manual steering box to trade

sorry for slow reply guys, I'm on the road this week. I'm told the box came off a mid-60's high performance Dart. The box is now in my '68 Dart in Portland, OR. A very experienced Mopar mechanic friend drove it and told me it needs rebuilt - there's a couple of inches "slop" in the wheel and it doesn't return crisp after a corner. Box is spotless on the outside, haven't seen the inside. This car is for my daughter and I'm thinking she would be happier with a 20:1 so that's the way I want to go. Looking to trade for a 20:1 box (similar condition OK), or maybe swap for a new 20:1 worm gear and I'll rebuild the extra 24:1 box I've got on the shelf. Thanks,
Bill