>>The DC-8-70F is not capable of using reverse in the air.
Uh, I wouldn't be so sure <g>...
Just be below 300 knots when you stow them.
Here's one reference:
"...One thing you might not know, the DC-8 can use and we do use them, specially going to San Jose, CA and JFK, the thrust reversers in flight. 2 and 3 can be used inflight to full reverse thrust. 1 and 4 can only be used when the gear is down."
http://www.forjets.netfirms.com/page3.html