Ridge reamer

You only need a reamer if the ridge is tall enough to prevent the rings from slipping past them, Typically, if you've got less than about .015" wear in the bore below the ridge, the pistons will come out with a small amount of persuasion. Anything deeper, you can knock then out with more force, but this will break the rings and/or pistons, but with that much wear, you need to replace them anyway. Putting back std bore pistons with .020+ wear, is a huge waste of time.

i always use a ridge reamer when there is a ridge at the top of the block. makes things easier on disassembly. one thing though, be very carefull that you DO NOT go too deep when removing the ridge otherwise you will have to over bore the cylinders. also remember that the ridge will not be consistant in it depth around the cylinder. this is because the pressure on the cylinder is different at different points, so dont expect to have a perfect cut the way around the cylinder. a tiny ridge is ok when removing the pistons. tiny being, if you can barely catch your fingernail on the ridge you are fine. more than that you need to cut a bit further. alsoTAKE YOUR TIME and make SMALL cuts.

Why cant you just remove the oil pan, crank and drop them out the bottom?aslong as you use pieces of rubber hose to "boot" the rod bolts should work fine. I dont know about using the rings again they are fairly cheap.

The pistons and rods will not come out thru the bottom for the simple fact that the bores are offset and the piston won't clear the main webbing.

I did a ultra budget rebuild on my Pontiac 350 in high school and removed most of the ridges, knurled the pistons, to fit the bore, etc and the thing kept breaking rings after that... Been there, done that... Had to run a rubber hose off the breather down to the ground to divert all the blue-white smoky blow-by vapor that was present when the engine ran. Needless to say, there were no mosiquitos within a mile radius of my car.

I would probably use a ridge reamer to get the piston out but not as a cure for a worn out bore. If you need to use a ridge reamer, then your bore is obviously in need of machine work that will render your old rings useless.

Uh, why would you pull out the pistons if you are not replacing them or the rings? I'll agree with Mr. Hearne, if there is enough wear to need a reamer, you need to bore the clinders anyway. If they don't come out, get a bigger hammer.

I don't think I understand what a ridge is...

Over time, the spot where the top ring stops on it's upward travel develops a ridge there, the top ring wears into the bore wall, the area above this doesn't wear at all, so it stays the same diameter as when new. The top ring ( and other rings too) in effect bore out the cylinder in operation. Now don't get this ridge confused with the carbon buildup that sometimes occurs above the top rings, the carbon can be easily removed, the ridge caused by the top ring wearing into the bore wall can only be removed with a ridge reamer, hone or having the block bored oversize.

Ahh, ok, thanks alot D.Hearne!