Finally, a question about pushrods that doesn't sound like "I have done x y and z to my car, I don't want to measure pushrod length and I don't want anyone to tell me I have to."
Comp Cams Part # 7987-16.
That part # is their Hi-Tech 3/8", .080" wall 4130 1-piece chromemoly pushrods, specifically in a 8.150" length.
I think you can go ahead and not worry about that extra two thousandths