What is the recommended gap between the bottom of the flipper bat and the playfield surface? Not sure if this is different from manufacturer to manufacturer, but I'm looking specifically at late Bally EMs and early SS Bally machines. I am planning to rebuild flipper mechs and replace flipper bats in this process. I would like to know what is correct as I reassemble.

Thanks

Thank you all for the reply and link.

I wouldn't spend any time on all that modification. Why not rebuild original flippers with all new parts? If he wants more power, change coils.

Get a rebuild kit from PBR. Your stuff is just worn out. The same original style replacement parts are available for now and will be for a long time. You could even get new base plates from Pinball Life. If you have a weak coil, do them when you rebuild. It is a night and day difference once both are rebuilt properly with new parts. https://www.pinballlife.com/classic-bally-flipper-base.html

If I got a machine with some modified flippers, I'd remove and go back to original. Just my preference.

Punch set. I setup on a block of wood and gently start the pin with a small hammer and then use an over sized punch to drive the roll pin in. Then I use the proper size punch to finish setting the pin to the correct depth.

I tend to use a drop or two of brake fluid on stuck bolts. I have used all kinds of penetrating oil and I have found brake fluid works very well. A small amount goes a long way. Clean parts once disassembled.

I had a rust bucket of a Bally a few months ago. Didnt break anything using brake fluid where certain things were caked in rust.