Just a quick comment on the Watts link. I found out that they can make routing exhaust more difficult. The Watts layout has one high link and one low link so that the pipes may not be symmetrical. I finally had to run the pipes under the rearend. I don't particularly like that solution, but that's what I had to do. Your 57 probably has a lot more room than my project did, so this may not be an issue for you. Just thought I would mention it.