Just for fun, I have attached the flow numbers for the 79cc S&S heads, they flow reasonably well on the intake, a bit less on the exhaust. I would dare to guess that the 585 cams were designed with these heads in mind, with the long exhaust duration to compensate the low exhaust:intake ratio.

I have been researching going from 95 to 107 on my 2002 FXD, the 4.375" stroke seeming like the most reasonable way. If I could only find a cheap set of 4.125" cylinders the all bore setup would be my choice since I can have the case boring done at a very low cost and I would reuse my crank, but the only cylinder option available here would be to buy brand new S&S 124" cylinders and have them shortened, and on this side of the atlantic a set of those cost like a small house

Anyway, since I too already have the 79cc heads I have done the calculations, with flat top pistons static compression is around 11:1, I was planning to reuse my Andrews 55 cams but I think the S&S 585:s would be even better.

I think keeping your S&S heads (maybe with a light clean up port job) and your 585:s will give equally good results as ported 06 heads and 570 cams to be honest. But thats just my amateur opinion of course

Here be the numbers:

 

I will go “Lefty” bearings sprocket and pinion. I can do that myself.

 

@SwedishMeatball Per your last post, you said you could have case boring done at very low cost which indicates you have access to a machine shop. I don't know what their capabilities are but cylinder sleeves can be purchased from MTC in Florida or Advanced Sleeve in Ohio. If the machine shop has the capabilty to accurately re-sleeve your cylinders, sleeves can be purchased for less than $100 each; don't know what shipping would be though. I ran MTC sleeved OEM cylinders on my all bore 107" motor; MTC fabricated the cylinders and cut spigots to fit my case bore. Just thought I would mention the possibility but I don't know if the cost of sleeves, shipping and machining cost would be any cheaper than a set of S&S cylinders and the machining to make them fit.

Go back to Max's post #41. It is a video of a motor rebuild that includes Max re-sleeving cylinders; you can get some idea of the process and judge whether or not your machinist is capable. Remember, Max did this at home but he does have a well equipped machine shop.

 

I do think the workshop that would help me with the machining is quite capable, I realize this might be going slightly off topic but there is a bit of info on their facebook page, they are doing a bit of cool Harley related stuff:

www.facebook.com/karlingracing

They were the ones recommending using cut down S&S cylinders, but I will ask them about the re sleeving route as well. Thanks for the information.

 

The OP was talking about 89cc heads, not 79cc. Since he's going with worked oem heads, try can be set up for the 570s he's decided to run. Not a bad choice.
Pick a good exhaust for them as well.
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I might have misunderstood but I think the OP actually has the 79 cc heads, but was planning on increasing the chamber sizes to lower compression when going to 117"

 

Yes this was the original plan. But now the plan is for oem heads for a 107 and if I go 117 later they will be suitable. 👌👍

 

The original post was wrong.. He corrected it later.

 

Got it.
Not the greatest pipe for this. Hopefully it's the long version at least and not the short megaphone.
Like the 585, the 570s have a lot of exhaust duration. I would look for results with that pipe and these cams or cams similar. The pipe will make or break it and I wouldn't leave it to chance. I ran those cams as a state 2 103 wih decent results but with the stock head pipes and Rush mufflers.
Who's doing the heads? Hopefully someone that understands the cam. The S&S heads would work well with them. That's not saying the oem heads can't do better.

 

So I have the long version of this pipe, stepped, equal length headers, works really well with my current build. It does tick all the boxes in terms of what a builder or tuner generally wants to see, so it will stay with the new build. It may not be the best but meh…

As for the heads I’m not sure yet who? I work abroad and am away now in the Falkland Islands until the New Year but when I get back to the UK I will start to gather the required parts I need and also find a head porter. Where I am right now a phone call costs a lot of money, so any comms with the real world is pretty much limited to email. Like myself and the many other veterans on here understand, there can be many difficulties of working away from home. It can be a PITA sometimes