Trevor

you can't tell if hydraulic lifters are good or bad by looking at them, you should have replaced them, the ends might look fine, but what about the internals of the lifters, they could be jam packed with burnt oil, near carbon and won't compress under load like they should, the centres of the lifters need to be able to compress. They could be running like solid lifters, this will bend push rods. I still reckon it is lifters

we paid $10AU each about 5 years ago for chrome molly pushrods My grandfather came from Invercargill

Don't forget to replace your lifters while you have the heads off, you will be sorry if you don't And shit that was a lot of money, but hell if it is better, then all good

we run anti-pump up lifters and chrome molly rods As an aside, do you have a high flow oil pump on it?

Some lifters will go hard, so probably best to replace them all