Heh, my mom had a red 510 wagon. 5 speed, too.

I've done a little reading on it and it's pretty straight forward. Actually putting the KA in a 510 is a popular swap in other countries. Prepare to spend some money. I'd compare it to doing a 240sx swap into a car with inferior everything. Then you get to tackle the restoration part once it drives.

By the way, auto trader has a classic car section. Prepare to spend 3-4k if you want a coupe in good condition.

Chris