Pipe is 1/2 inch black iron and the angle is just shy of 22 degrees. I have made several with good results but have an original for a pattern. They are available from a couple of part suppliers if you wanted to buy them ready made.
Welcome to Oldgas. I seen your post in new member forum. Nice pump. I would think it would be tough to get them right without a pattern. They are not that expensive from suppliers. If you have a burning desire to say I made these good luck.