As long as they fit the thread in the rocker arm and are in good condition, no problem. I just have a thing about getting robbed by companies who think they have the market cornered on parts for anything. Jesse James had to use a gun to steal from people!
I cut the ends off the original pushrods about 1/2" to 3/4" long, grind a slight taper on the shank to help it center in the tubing, and use a hammer and a brass drift to tap them into the tubing. I make a holding fixture from two pieces of square key stock bolted together with a hole drilled between them to clamp the tubing into and support that in a vise. Since the rod is in a "push" situation, no welding or soldering is required. It's the same way millions of tubular pushrods for all sorts of engines have been made for over a century.
Jerry
