I got my pushrods from Butler performance in Lawrenceburg, TN. They actually have Smith Bros. make them. They were dropped shipped to me so they came fast. I got 12 each, 3/8” X .145” wall chromoly, 3/8” ball on the lifter side, 5/16” ball on the rocker side, 12.500 OA, exactly 2 years ago. Cost me $233.00 at that time. I'd join in the discussion, but I'm working on a GMC 302. However, I believe the original builder used Chevy Big Block roller lifters for this project.