Slow crank

Ok guys. Again thank you for the help. I started with the volt meter test until I popped the internal fuse and died! JML I went to buy another one sadly I live in one of those geographically challenged areas where no one is open on a Sunday lol started tracking down all the wiring. I think I may have found the problem! To me I think the starter bolt that the positive lead runs to is making contact with the block! Its tight. There might be enough room for a piece of paper to go imbetween the two. If I get some time thru the week after work in going to drop the mini starter out and put a different one in where the post face a different direction as well as run a few new ground wires.
While I was cranking not having a working volt meter I hooked up my timing light which will not regester with less than 12volts so obviously there's a huge voltage drop from point a to point b. But where is the question?