72 or 73 and up 3/4 ton master cylinder???

[70rs/ss]

Like the title says, are you guys upgrading your 1/2 ton Blazers with the 3/4 ton master cylinder and booster from the 67-72 vintage or are you using the 73 and up 3/4 ton stuff?? I looked at NAPA yesterday and the mounting flanges are different, but I am sure they both could be made to fit?? Let me know as the price is the same for both, so if one fits better or they both work the same let me know and I'll use that one!?

Thanks for the help!,
70rs/ss