It?s been a long time since I did that step, but I know it can be done without removing the pushrod tube.
You just have to try different approaches until you find the right combination. I come in from above and to the side. It has to flex right to the point I think it will take a bend before it slides in.
Also keep an eye on the cylinder wraps on the bottom inboard. They tend to catch on the fins and need to be helped in by reaching under the cylinder and pushing them out while working from the top to slide the baffle in.