worthwile to put a 5 speed in a 540/6?

[jbraswell]

I've been looking around for a 6 speed for my 540i. The only ones that I've found have been $1500+.. Thats what I have in the entire car. How bad off would I be with a 530i 5 speed, and what modifications would I have to make? I'm sure the gears are probably taller, but with a 3.64 LSD would the performance difference be enough to spend twice as much for the 6 speed?

There are 3 5 speeds within 200 miles of me with less than 120k all for less that $800... For that price I'd almost assume take the risk on a used 5 speed. What, if any, modifications would I have to make, or better yet, has anyone on here done this swap?

I did search, and found that it was plausible, but not much info other than that