how strong is the 8 3/4 #741 case?

rebelcaptain said
Nothing wrong with the stock 3:23 gears

I don't have the 3.23:1 gears anymore. They would be acceptable, but right now the only gears I have are 3.55:1 and the mileage is terrible. Here in California, premium gas is near $6 per gallon, and it used to get 17 mpg with the stock 3.23"s.