I like the new all billet case Traction locks, I have one for the ( original) 3.50 open diff for my 68.5 CJ . I built an extra ( keeping the original C/R in tact) Wide ratio big /out toploader for better street manners. 3,000 rpm on the freeway isn't bad. I would switch to a 3.00 "if" I was planning a long drive. Right now it has a 4.30 for "spirited" short drives and I stay off of the freeway with it.
'66 GT350H-3 time cover car - Car Craft July'77,Modified Mustangs and Fords Feb2011 ( w/article), Mustang Monthly June 2014. Bracket raced by me for the last 44 years. Yes it is a real one.
'68.5 R code GT fastback
'67 Ranchero 408W -427 glass hood
'78 F350 "Oleynik" car hauler
Ford Experimental parts collector