I looking for 4 replacement lock/jam nuts for for Harley's Screamin Eagle Premium Tapered Quick Install Adjustable Pushrods, part # 18404-08. Harley does not sell them separately. I picked them up at a swap meet without the lock/jam nuts for a great price.

 

Could you take one of the rods to the hdwe store and match the threads to a stainless steel or grade 8 nut?

 

yes go to the hardware store, they have nuts that are half the thickness of a regular nut, but do not buy a distorted type locknut as you will not be able to unloosen it after it has been installed without destroying the pushrod.
I am attaching a photo to give you an idea of the half size nut.