Quick XS400 question, Thanks!

Hey guys iv been working on my 1977 XS400D for a few months now and iv been trying to find a set of carbs that will work. The carbs that came on the bike were a un matching set that just aren't going to work... So Iv found a guy selling a basket case XS400 for $200 not to bad. So what i really want to know is will his carbs fit my motor.
(i have already bought 2 sets of carbs that did not work, one was from a XS650 i was going to try and swap parts to get them to come in closer because the xs650 is a wider motor then the xs400. Then the other set was from a xs400 but they look nothing like the carbs that came off my bike and were closer together then stock carbs, so im thinking they came of a 83 xs400 or a DOHC xs400 motor.)

So here is my Q will the motor and carbs that he is selling fit my bike? From what I have read any SOHC xs400 motor will swap. But will the crabs swap between motors?
I may also want to swap motors will the motor he has fit in my frame (my bike is a 1977 XS400D he never said what year that bike he has is)

Here is the motor that comes with his bike


Here is a link to the listing
http://fayetteville.craigslist.org/mcy/2920320252.html

Looks like the same carbs and the only thing that looks different from my motor are the fins.

Here is my motor





So what my plan is to first pull the carbs from the parts bike and put them on my XS400 to get it running. Then also grab some other parts like the pipes because they look better then mine. Then I might pull my motor and rebuild it using the best parts from both motors. Or if something goes wrong with my stock motor i can swap the motor from the parts bike into my bike.


Thanks for all of the help guys! I just don't want to spend more $ on parts that wont work and it a good little drive away from me.

Here is a link to my build
http://www.dotheton.com/forum/index.php?topic=33288.0