so I'm sure this has all been gone over, and I searched and found sprinkles of info here and there, but I'm still confused as to why an NV4500 conversion requires a "conversion" bellhousing? 
I was under the impression that the 1st gen blocks and cranks were the same as the 2nd gen blocks and cranks... aparently that's not true. where exactly are the differences?
I appologize for the elementry questions...
TIA,
Forrest

I was under the impression that the 1st gen blocks and cranks were the same as the 2nd gen blocks and cranks... aparently that's not true. where exactly are the differences?
I appologize for the elementry questions...
TIA,
Forrest