Here you go...
#1...1-1/4" parallel drop, 14-3/8" LOP, MC
#2...1-3/8" parallel drop, 14-3/8" LOP, MC
#3...1-1/2" parallel drop, 14-3/8" LOP, MC
#4...1-1/2" parallel drop, 14-3/8" LOP, Straight comb (no MC)
The adjustable rib 90-T had...1-1/4" parallel drop(some were closer to 1-1/8" drop) This is measure from the higher rib. If placed on a std 90-T, the comb would be 1/2" higher.
Just one more thing....The std 90-T also had an upgrade of wood as an option. This option also had a much larger checkering pattern on both pieces of wood. This is how you can tell the difference.
Doug Braker