Can anyone tell me the length of the upper, inner tube, in a Shovelhead pushrod tube assembly? I only have Sportster ones and there 4.5" long. I need to make longer pushrods and tubes for a Sportster with taller cylinders and I have heard that using the Shovel parts will do it. While I'm asking, whats to od of that tube, just to be sure. I know that the pushrods themselves won't interchange, but I found automotive ones I can use. Thanks in advance.