I got 2 rx7 FD seats and im trying to put them in my FC but the sliders and brackets dot fit there to short. Anyone know what to do??

 

Of course they don't fit. They are from two completely different cars.

You'll need to compare both brackets side by side and figure out what needs to be modified. Generally you can just weld some tabs onto the FC brackets to match up with the seat you want to install.

 

Can't go wrong with stock seats i wonder if thre is a problem like this with the rx8 seats?