advantages/disadvantages of mt75 box?
 

What are the advantages and dis advantages of using a mt75 gearbox apart from having to change the transmission tunnel?

It seems to me that it s easier to get a sierra with a mt75 box now than one with a type 9, as i want rear discs too.

MT75 is a lighter, aluminium housing, gearbox which can also take a little more power. However, its considerably bigger than the type 9 gear box, so isn't as popular in a car where space is at a premium. Its also worth bearing in mind that spares and quality upgrades are aimed at the type 9. You can get any upgrade you can conceive for a type 9, if your pockets are big enough

MT75 has a synco-mesh reverse gear. Good for auto testing;)