i didn't know people used ridge reamers anymore.

If its a OLD block.. they were soft(before they
started putting more nickle in them) you HAD to
use a ridge reamer to even get the piston out of
the bore.. yeah I still own one somewhere around
here but havent used it in over 20 years(maybe 25)

If you're not boring or power honing the cylinder then ignore the recommendation to ignore using the ridge reamer and use the ridge reamer. It's not rocket science. You may be able to rent one from an auto parts store.

If the new top compression rings run up and over a ridge at the top of the cylinder, even after use of a ball or three finger glaze breaker, it will destroy the new rings and pistons. Even if you use the same piston it will destroy the rings and piston because the new bearing raises the piston height in the cylinder, even thought it's only a thousandths of an inch.

Removing the ridge isn't just for ease of piston removal.

It's easiest to use before piston removal because you can square the tool on top of the piston. It's not rocket science unless you're the guy that screwed it up for JohnRR, and the instructions are an easy read.

i was thinking about a 360 i put together. this was 100,000 mile dakota engine. always unleaded fuel and the oil changed religiously. from what i can remember running a dial bore gauge thru the cylinders that there was next to none taper! that 400 may not have a ridge; if taken care of.

I bet the moly rings, harder block and superior efi fuel control had something to do with that.

Every block I had come into the machine shop where I worked that had a ridge reamer used on it was screwed up. Not all, but the vast majority of people will remove way too much material from the bore w/ a reamer.
I've taken a lot of motors apart that had big ridges and never used a reamer. Not worried about saving the pistons, so I just knock em out. If it has a big ridge, the pistons shouldn't be getting reused.