Just off the top of my head, I seem to recall that under the 1990s pattern, an Armored Division had 5-6 battalions of armor, 3-4 battalions of mech infantry and a cavalry/recon battlion with some tanks in it.  In a Mech Infantry Division it was 6 Bat. of mech inf. and 3 of armor plus the Cav. Bat.  It generally worked out to about 350 tanks for an Armored Div. and 250 or so for a Mech Inf. Div. 

In Division 86 structure both divisions had 10 maneuver battalions 6 tank and 4 mech in a armor division, and 5/5 in a mech division.  There was also a cavalry squadron.

 

58 M1s per battalion' 27 in a cavalry squadron.

 

This is wht we went to Desert Storm with. 

 

From about 1992 until we went brigade centric, we went 5/4 as a rule (armor 1 more infantry 1 more) but this was violated as much as it was followed.  And it also did not extend into fully into the National Guard.

 

Also by late 90s we dropped 1 tank company per battalion so went to 44 tanks per battalion.

The army uses a light heavy system now, basically the mech brigades and battalions are the same as the armored brigades and battalions. I actually liked the old system when there was a difference between the two. you gotta love the cadillac infantry. basically the mech units were Bradley heavy. but then they were broken down into task forces and teams in a field environment