[V8] 3.6 to 4.2 swap

[Thomas Barbera]

Fellow V8 fans,
I am in need of a clutch for my '91 V8 5spd.  I'm
considering (while I'm at it) swaping my 3.6 for a 4.2
from my brother's car ('93 v8) which just lost its
slushbox.  I know there have been write-ups in the
past on this issue but I can't find them.  How
difficult is this task?  My motor is tired (200k
miles) and needs a top end rebuild if I don't do the
swap.  I found a few threads that suggested it is a
very difficult swap.  I find this hard to believe
considering the similarities of the engine bays and
wiring harnesses.  The only big issue might be the
manual tranny/4.2 mating.  Anyone have any pointers? 
Can you put me in the right direction?  What parts do
I need?  I have performed in the past an MC conversion
in my old '86 4kq.  It surely cannot be nearly as
difficult as that project.  Thanks in advance.

Tom B.
'91 Audi V8 5spd