bent pushrods?!?! wtf!!

I have run a medium cam and dual valve springs, to 7,000rpm and not bent stock pushrods. Since the engine was rebuilt, the things I would look at are:

1) valve guides too tight, especially if the bent pushrods were exhaust.
2) coil bind of the valve springs. This would depend on how big a cam, and which springs were used.
3) The spring retainer hitting the top of the valve guide.
I lean toward number 1 or 3.

On a 225 engine, unless you milled the head a lot, and are running a pretty big cam, I doubt the valves are hitting the pistons. (providing stock pistons and con rods). How much was the head milled, and what are the specs on the cam?