to quote my wife, "bigger is better". Yes, go for it, especially if your doing the work yourself. Get the cylinders bored and do the flat top pistons (not as good compression as domed but your better off if not going racing). The
.30 cometec head gasket and if your doing the fuel moto thing already, I assume your doing the woods 6-6 cam. I just spent the last 3 hours with the local HD mechanic on this same subject. I figured I might as well do the same thing your doing but he is talking me into the 7-h cam or something in that vicinity + valve job and springs. He did mention that he liked the se 251 but thought the 255 was not very good and after I explained how people were happy with it on this site, he showed me a few dyno charts of the cam/after tuning and it really wasn't that impressive. Too close to stock for me to even think of upgrading to it and the torque curve people mention was not showing up on his dyno's. I will really be watching this thread to see what progress you make. I hope you know a good tuner to finish things off to get the best out of the package. Good luck.

 

Thanks to all for the input so far. It sounds like its a reasonable direction to take. I suppose I should have added that I'm not seeking the ultimate bad *** high power/high torque monster, just an appreciable upgrade from stock. I have been enjoying doing this in stages and will continue to do so, for the time being.

One poster suggested that I call Jamie at Fuelmoto to discuss a displacement change and that is very good advice. I have been pleased with the suggestions I have received from Fuelmoto so far and as I am using their PCV, a remap is pretty easy, regardless of what I do ultimately.

I must admit that, for me, part of the enjoyment of owning my bikes is the time spent working on and improving them. It's one of the reasons I enjoy doing the upgrades in stages, so that I always have something to plan and look forward to in the winter months. In reality, it is the power and responsiveness of my Cross Bones that I would like to get close to with the Ultra. The Bones, which has the conical SE air cleaner, SEST and Big Radius pipes, runs like a raped ape. Now clearly, the real difference between the perceived engine performance of the Bones and the Ultra is all about the power to weight ratio of the two rides, as they are essentially in the same state of tune. The extra weight of the Ultra is what I am trying to off-set, somewhat.

 

if you wanna be 100+/100+ you gonna need some head workand some different parts... save your money and do it rite the first time...talk with different tuners and get parts that work together....jmo