Put ice in a garbage bag and lay it on the flywheel for an hour.

I use dry ice instead.

Ring gear is only $30 (plus shipping) from Rock Auto.

https://www.rockauto.com/catalog/x,carcode,1209316,parttype,5360,a,Search%2Bfor%2B1983%2Bnissan

Thanks everyone for your advice... I had it machined today and found the ring gear to a 280 at Autozone for $25. It will be in tomorrow and I will be able to compare them. If that one doesn't work, I will get one from rock auto. Thanks everyone for your advice. I will let you know how it goes.

Picked up the ring gear (for a 78 280) and it looks to be identical. I will be putting it on in the next couple days. I will be replacing the clutch also... any advice? Brand etc. On a budget and primarily for street use...

Update;

I replaced the ring gear using an Oxy/Acetylene torch at my buddy's shop and saved myself $45. Here are some YouTube videos I that helped a bunch.. I would suggest you heat it up on blocks like in on the first video. Also, a mechanic told me that you can use a propane torch which I unsuccessfully attempted. It didn't help that the torch wouldn't stay lit. Still, I would suggest you use a Oxy/Acetylene torch. It was much faster and easier. We heated it up and it dropped right on. Just make sure it seats all the way down. Hope that helps anyone planning on doing the same.

http://m.youtube.com/#/watch?feature=related&v=yYvGXTDjY4w

http://m.youtube.com/#/watch?feature=related&v=_XW1-5mPSsY

Good luck and thanks to everyone for your advice.

Chris