Bad vibes.

I had never heard of a steel crank 360 either. But when I saw this I thought ok, maybe. Vibrates in neutral so not DS. Flex plate only fits on one way. Engine came out of a friends van. He said its never been opened up. If the cam timing is wrong im not changing it. Runs like hell for what it is. We built this about 2 yrs. ago. He don't drive it much because of this. I'll check everything suggested. Thanks.