So I ordered a Malossi 70 kit for a Yamaha BWS. The last kit that I used was NCY for a Yamaha Jog. Here are the two kits side by side with a few notes...

the NCY uses the copper gaskets, while the Malossi uses a rubber ring. It looks like the Malossi has a bit more compression than the NCY. At first I didnt like the quality of the Malossi.. the cast was a bit more rough, the exhaust hole is smaller than the NCY.

Here you can see the difference between the two transfer ports. Notice how on the Malossi (right side) the transfer ports are rounded on the bottom, thats how the case ports are shaped.. so it matches the case better than the NCY kit, which are squared all the way around...

Here you can see that there is and extra cooling fin on the Malossi...right now im running a OKO 28 with 72 pilot and 150 main, middle clip on the needle...
I have a Stage6 kit coming in the mail.. Ill update when it comes in...