ty754vn1aa which diff head?
 

hi all
Just wondering what diff ratio i need at te back for this box. Its connected to GC8GK8D engine from a MY99 wrx. There is no sticker on the gearbox though, im ony going by the build plate. So yeah what final drive should i be looking at?
thanks

Form checking the gearbox chart it should be a 4.11 final drive on your box but be carefull as some of the UK gearboxes seem to have different dropgears which change the ratio for the rear diff (from what i've seem the dropgears were 1.1:1).

Have a read at this thread for a bit more info:

https://www.scoobynet.com/drivetrain...ff-ratios.html

Do you have the old diff you could check the ratios on?

No it shouldn't. Where is the chart you're getting that from? Suffice to say it's incorrect.

Can you be a bit more specific (well, correct) on the type of car you have? GC8GK8D isn't a "WRX", this applied model code is a UK specification 1999 model year "Impreza Turbo 2000". The difference in the names is significant, as at this time, "WRX" was a Japanese market model. Which one do you have? Edited to add - this is an Aus market car, isn't it? If so, WRX is prob accurate - but you need to specify the market as you'll confuse the hell out of those of us in the UK. ;)

Are you sure there isn't a sticker on the box? If it's there it'll be on the bellhousing, next to the starter motor.

If the gearbox is a 754VN1AA, it has a 3.9 front diff ratio and 1.1 drop gears - meaning that you need a 3.545:1 rear diff to match it.