Personally I don't see how ... The 250 z-bar would be too long to fit between the frame rail and engine block. Perhaps the z-bar was cut to get it to fit ...
I have some old Mustang z-bars. The 6 cyl ones are probably about 3-4 inches longer (frame to block) than the v8 ones. The Maverick shouldn't be any different.
I just fit the only cut I made was to the bottom because of clearence issues with my headers. The bar was very sloppy with the six and still sloppy with the eight. I'm assuming it was a 6 bangers z bar cause I got it from a 74 Mav 250 3spd car I bought for parts. I never had the title so it might have been an 8 that someone threw in a six and the 3 gear just sell a running car.