Am starting to put a generator setup together. I'm planning on setting up an interlock and backfeed breaker into my panel with an outdoor receptacle for the gen to plug into. The issue is this. My generator is older(its an old garden way with a cast kohler engine, 5500 and runs like a top), and is setup with a NEMA L6-20 for the 220 which I'm planning on using--it also has two standard nema 5 outlets. This means it is straight 220...so, can I just wire the whole thing 3 wire, no problem? meaning in the panel, the 2 hots to the backfeed breaker and the grd to the grd bus bar? Am I missing something, or do I need the neutral?  

Thanks in advance for any input!![enter image description here](https://i.stack.imgur.com/dlse6.png)![enter image description here](https://i.stack.imgur.com/f1SG0.jpg)![enter image description here](https://i.stack.imgur.com/BK1X7.jpg)
[![enter image description here](https://i.stack.imgur.com/51NOt.jpg)](https://i.stack.imgur.com/51NOt.jpg)