Funny because I ran into the same issue after rebuilding flippers on the same game.

You say you rebuilt the flippers. Did you replace the EOS switch and capacitor? Either way, check the resistance across the closed EOS switch. Should be less than .5 ohms (half an ohm). If more than that, file or sand the contacts to get it lower. New EOS switch contacts often have oxidation on them and all the power for flippers goes through those contacts. If you replaced the EOS wires, make sure the new wires are 18 gauge. Flippers use a lot of power and need big wires to move that power.

Same goes for flipper button switches. Clean those contacts too. 400 grit sandpaper works fine on new high power contacts.

Once you're sure the contacts are good, make sure the EOS switch isn't opening too early. Should be 1/8" gap at the most when flipper is all the way up. If it opens too early, you won't make the right ramp.

Lastly, check your pitch. Should be 6.5 degrees tops.

Power off when testing.

Virtually every brand new high power normally closed EOS has resistance issues. The contacts are made with metals that encourage corrosion. The corrosion isn't visible to the naked eye, but a meter will quickly show differently. I've had brand new switches register over 50 ohms of resistance. A light sanding usually gets you under 1 ohm. Are you sure you checked yours?

It shouldn't be anywhere near 90 volts. Try another meter. Should stay around 65 volts. If it still goes up near 90, high voltage section needs repair.

Even with rebuilt flippers, the right ramp shot isn't easy. Especially from a cradle. Should be able to shoot the right ramp from a cradle, but not by much power-wise. Try replacing or swapping the caps across the EOS switches. I got one from PBR that wasn't right. You haven't mentioned if you checked to see if the EOS is opening too early. Do so if you haven't already. Pitch doesn't look too steep in the video, but verify you're at 6.5 degrees or less *between the flippers* with a digital level.

Good point. He asked more than once about the voltages and I knew 90 volts was too much. I checked mine because it didn't sound right. Bad meter, wrong settings or test points, but 90 volts should definitely not be happening for real. Right ramp would be easy money at 90 volts.