Would this be possible,and what good would come out of it.

 

its the same crank.

 

If it's the Prelude B20A (and I assume you mean B20A5 not 6, there was a 6 in europe, but the 5 is what's here in the states), then they are not the same.

The Prelude has a 95mm stroke. The Big end bore of the rods is the same, as are the crank journals. I don't know if it'll fit for sure, you might have a problem with the timing gear and pulley being too close to the block