No, but 181 flanges WOULD allow you to use bus CV's (big) or 944 CV's (bigger). Most of the racing transaxle shops have their own 181 type "conversion" outputs also but are more $$. You don't "have to" go away from T1 CV's at all unless you intend to abuse them (which I definately intend to do
).
A link to some comparisons of the different sizes of the CV's and axles.....
http://www.blindchickenracing.com/Ho...es_and_cvs.htm