Punctuiation and paragraphs will help your cause in a big way.
As far as your question goes:
Most people selling a 'T-series Center' will sell it as a complete center, i.e. the aforementioned front housing or 'nose', the crownwheel and pinion gears, all lashed up and complete as toyota intended.
If someone is selling just the crownwheel and pinion gears without the housing, it will generally be advertised as just 'x.x ratio T series gears'
If i haven't answered your question then PLEASE rephrase and use some basic punctuation.