Had a cracked plug on a F-body. It does mess things up. It seemed to be running OK except that it seemed a little flat.

It's the original 87 700R4? It could become an issue, especially since it has wear and tear on it.

I like the engine but personally I'd put a little more cam in it.

I think his site has some decent info. I can't say if it's all good or not. There have been lots of complaints about the tuning over the years. It's best to confirm between a few sources before...