Having it off 6 degrees isn't terribly unusual. Either get a timing set that has multiple degrees on it, and some degree ecentrics and get it perfect.

It may have nothing to do with the crank, it can all be in the timing chain set, or the way the dowel was installed on the cam. Its really why we degree the cam in the first place.

I did a Chevy once that was so far off we had to slip the chain/timing mark one tooth, then put the biggest eccentric in the other direction to get it right.