I've only ever bent one pushrod in the years i've been racing the A-series.

The cause - dunno, just put it down to high revs.

Just for interest sake, it's very easy to change a push rod quickly if needed in an A-series...

Loosen your rocker adjuster right off, slide the rocker along the shaft against the spring, remove bent pushrod, put in new pushrod, let rocker go back to position, adjust clearance, off you go.

Like I say, had to do it once in a 20 minute service, job took less than 10 minutes.

This is why I will never use the aluminium rocker spacers you can buy, turns a simple job into a very lengthy one.