How much and where do u get them at. which ones do u suggest?

 

I have the black spring in my driven pully and the red spring in my front (drive) pully. I love them both...Stock drive spring has a smoother take-off but I really like the way the red spring launches you. You can still take off slow but you must be a little more careful with the thumb.

Thier sight is http://www.erlandsonperformance.com/ but you will need to call to order. 218-829-6036