318 has been sitting for 2 years

The backfire has me wondering about whether or not the plug wires have been monkeyed with. You might as well make sure the ignition is squared away from the dizzy on out. If you're not sure of the timing, you can try to statically time it.

Yeah I am wondering the same thing. Kinda bothering me that its not firing up even with a quick spray of carb cleaner.
I have an msd distributor. Is it possible to insert the distributor 180 degrees off and cause the timing to be way off? Because thats all I can think of. I removed the distributor to give me more clearance to insert the top two bellhousing bolts. So I am wondering if thats the root of all this because I marked where the distributor was before taking it out and inserted at the exact same location. Any idea?

What do you mean by statically timing it? Do you mean to take out the spark plugs and get cylinder one to TDC?