[Mr70]

"Although not as common as 373 or 410, 355's are not that rare. I am not sure if is documented but i have heard of a car z with 331's. Those higher gear ratio require a wide ratio trans or they are a real dog to get going. 373 was the standard ratio for a 69 z, the others were optional.'

That sounds correct as I always thought these were the gears possible when ordering the 1969 Z/28.
*3:73 was the Standard ratio.
*3:55 was the Economy ratio.
*4:10 was the Performance ratio.
*3:07 or 3:31 were the Special ratio.
All come w/8 & 7/8" ring gear.