Your drawing is rather inaccurate. Your rear springs have negative, not possitive arch to them.
![Green Grin :greengrin:](https://board.marlincrawler.com/Smileys/marlin/greengrin.gif)
But you have the idea down correctly. It should be fine how you drew it but one thing that needs to be considered is how stiff are the rear springs? If they are very soft and twist up you'll need a bit more downward turn.