Looking for Molder hold down ideas adding spring tension

[chip5774]

Has anyone ever modified there hold down on your molder? I'm wondering how you did it. I have an older 4 side molder with a adjustable solid steel hold down and I'm looking to add some spring tension to it. I have a customer that I two side rough cut lumber for it's usually very accurate but looking for an idea to maybe add spring tension to my hold down maybe Coil or leaf spring or something with tension and a little give to it for wood that's mostly the same thickness but you get a few thick n thin once and a while any ideas or pics would be great  thanks so much