Does anyone know of a difference between a 13B N/A out of an RX-7 from Japan and a 13B N/A out of an RX-7 from North America?

The reason I ask this is because the engine in my 88 GXL is pooched and Im lookin to get it rebuilt.

I called up a company here in Toronto called "A-Spec Import Performance" and they game me a couple quotes:

-To rebuilt my engine if I bring them just the block: $1600
-To buy a used engine from Japan from them: $1000
-To buy a rebuilt engine from Japan from them: $1500

So apparently it only costs $500 for them to rebuild an engine that they get from Japan, and $1600 for an engine that I can give them tomorrow.

I DONT GET IT!!!!!

If someone could explain this that would be GREAT!

Should I get my engine rebuilt?
Buy a used engine from Japan from them (with no warranty)?
Buy a rebuilt engine from Japan from them (1 year, unlimited km)?

The engine is ready to come outa my car, as soon as my bro and I finish weldin together our engine hoist it will be out and good to go.

Can anyone offer any advice?!

Thanks a bunch!

 

First off, all Japanese 13Bs are turboed. They did not sell N/As in Japan. The used Japanese engines should at least be warranted to run. If not, get the rebuilt Japanese engine. No matter what, I would go with a Japanese engine because it's going to make a lot more power.