The biggest enemy of any transmission aside from deliberate abuse is
heat. Three years ago I had the 727 in my Coupe rebuilt and
simaltaneously had the largest stack plate transmission cooler B&M makes
installed. After three scorching Texas summers and several 100+ mph runs
down I-10 & I-45 the fluid still has the colour of pink lemonade. The
tranny still shifts the same, no slippy slide or mushy shifts firm as a
cheerleaders butt.
Marc
'67 Coupe