New shortblock shelf life?

So my 347 short block has been sitting around in the garage for something like 2 years now I've been good about turning the crank now and then just in case. I've kept it on the engine stand, wrapped in a vented garbage bag since I got it. I've occasionally sopped motor oil all over the whole thing to make sure all the surfaces stay nice and oily. So far (knock on wood) it hasn't shown any signs of corrosion on any of the critical surfaces. I also live in AZ which helps.

How long should the engine be safe like this? I know the second I see any corrosion, it's all over and I don't want the $2400 I put into it to go down the drain before I have a chance to run it. If I hadn't spent so much money on bicycling, this wouldn't be an issue

Yeah I would love to get it done. Money priorities is the issue. I bought a house instead of heads. Then spent $1500 on a mtn bike instead of heads now we're spending a few thousand on a trip to Alaska instead of heads and on and on I could in theory finish the motor right now, but I'd be in deep doodoo with the girlfriend. I'm hoping by the end of the summer I can have a nice chunk of change allocated to this specific project and I'm not a fan of using the credit cards after learning my lesson back in college.

I'm not sure about the problem with storing it on the engine stand instead of something more 'natural'. Although cast iron isn't very elastic, it doesn't 'creep' over time. So if putting it on the engine stand would effect it, it would have already done so unless there is deep-seeded corrosion involved. That's just my theory anyway