Gearbox MY96WRX

HI all
I am looking to replace my gearbox as its getting noisier.

Can anyone tell me if an STI box is the same.
Reason for asking is , i can get much later gearbox with low miles from MY 99 Sti

I have know idea at all about the ratios and compatability between makes and year of manufacture

Thanks

[andy-m]

look here:-
http://www.catherineandken.co.uk/sti/trans.html

check your gearbox number with the above link for the diff ratio (Final). make sure whatever box you are replacing it with has the same final drive ratio as what you have now. if not, you will need a matching rear diff

[2-jaffacake-tone]

Impreza boxes are interchangable, the later boxes have an extra 4 bolts in the bell houseing witch you dont use as you wont have threads in your block, There is only 1 slight issuse,You have to modfiy your lower starter motor bolt, as yours has a stud an an 17mm headed nut. The later boxes have a hole where a bellhouesing bolt would go though witch you cant use.

As mention make sure you have the right matching diff