So you want to make your B into a T? I'd bet that it'll be more trouble that what it's worth. At first guess, I'd say as a minimum, these would be different:
Shock Towers
A-Arms
CVD's (F/R/C)
Chassis braces
Your best bet is to pull up the pdf's of the two vehicles and compare the P/N's against each other.
T:
http://losi.com/ProdInfo/Files/8T-Parts-List.pdf
B:
http://losi.com/ProdInfo/Files/LOSK0...GHT_Manual.pdf