I'm keeping the 883 heads as is for now due to not much money issues. There is no valve work needed that I am aware of. Of course a head job or 1200 heads will be better but using just the stock 883 heads should be pretty good by itself.
Take a look at this chart from the NRHS site.



It says The bike that generated this dyno sheet is also equipped with a HurricaneFlow Air Cleaner, Mikuni HSR42 carburetor, SE .536 cams, Supertrapp exhaust system, and Daytona Twin-Tec ignition.

I don't have the cams or the ignition they are using but I do have the SE a/c, stock carb and SE II slip ons which is comparable to their setup so I'm expecting somewhere around 70 max power according to that chart. Should be a good boost.

128 auto the kit comes with cylinders, pistons, rings and gaskets. I went ahead and bought a top end gasket set for an extra $30 I think it was. The guy at NRHS said the bottom row of cooling fins needs to be ground down a little to fit but other than that it should bolt right on.