Stop flywheel from moving? (automatic)
 

I need to somehow, seize the flywheel so I can change the crank pulley. The new pulley is the Kartboy, so the crank tool isnt an option. Any help?

Hi. welcome.

Not super relevant, but you don't have a flywheel. It's an automatic. You have a torque converter and a flexplate.

A few solutions for you:
If you have the crank tool, use it to get the stock pulley off. If you don't, be creative.

If you need to jam the motor in place, you can pop the starter off and use something to jam the ring gear. It's attached to the flexplate in your car, and would be attached to a flywheel if you had one. I wouldn't do that, but it's what came to mind.

Otherwise, I recommend you use the tool to remove the stock pulley, put the kartboy pulley on, and tighten the pulley most of the way... The motor doesn't turn over that easy. after that, the pulley will be held in a fixed postion relative to the crankshaft (by the keyway in the back of the crank spacer and the key pin in the front).. use a big strap wrench (the rubber ones for oil filters) to hold the crank shaft pulley in place while you torque the bolt.

If you don't like either of those suggestions, you could pull the transmission entirely, unmount the torque converter, and grab a flexplate bolt with a socket. The torque converter mounting bolts will not work as they are rear-facing and turn the wrong way for what you are doing, so it'll be a bit of a process.

Oh, and I have one suggestion that's even worse than all of those. You're going to hate it. Hell, I hate it, but it involves throwing out the torque setting and using a impact wrench to tighten it, as the wrench will deliver torque faster than the crank and rotating assembly can comply. It'll be tight... I'm only suggesting that for a laugh. Please don't do it. But hell, I don't see a great reason to do the mod in the first place, I'm just helping. I'll leave my opinion out of it.